Que signifient vos résultats d'analyse ?
Vous avez reçu un rapport de laboratoire ? Voici ce que signifient les paramètres les plus courants, les valeurs de référence (EPA et Santé Canada), et quoi faire ensuite. Ce n'est pas un avis médical.
Reference values verified 2026-10-27 against EPA primary/secondary standards and Health Canada Guidelines for Canadian Drinking Water Quality summary tables.
Aperçu rapide
| Paramètre | EPA (É.-U.) | Santé Canada | Santé ou nuisance |
|---|---|---|---|
| Total coliform & E. coli | E. coli MCL is a treatment technique goal of zero (none present). A positive tot… | E. coli MAC: none detectable per 100 mL. Total coliforms are used as an operatio… | Health risk when E. coli (or enterococci) is present. Total |
| Nitrate / nitrite | Nitrate MCL 10 mg/L as nitrogen. Nitrite MCL 1 mg/L as nitrogen. | Nitrate MAC 10 mg/L as nitrate-nitrogen (45 mg/L as nitrate). Nitrite MAC 1 mg/L… | Health — especially infants under 6 months and pregnant peop |
| Iron | Secondary MCL (SMCL) 0.3 mg/L (aesthetic). | Aesthetic objective (AO) 0.3 mg/L. | Mostly nuisance (stains, taste). Very high levels can affect |
| Manganese | SMCL 0.05 mg/L (aesthetic). EPA has also issued a health advisory for bottle-fed… | MAC 0.12 mg/L; AO 0.02 mg/L. | Both — stains at low levels; health MAC protects bottle-fed |
| Hardness (calcium & magnesium) | No MCL. Often expressed as mg/L as CaCO3; 'hard' water commonly starts around 12… | No health-based MAC; aesthetic/operational issue. | Nuisance / plumbing — not usually a health MCL issue. |
| pH | SMCL range typically 6.5–8.5. | Aesthetic objective generally 7.0–10.5 for treated distribution systems; private… | Indirect health risk via metals (lead/copper) when corrosive |
| Sulfate / hydrogen sulfide | Sulfate SMCL 250 mg/L. No federal MCL for H2S (odor-driven). | Sulfate AO 500 mg/L. H2S is primarily an aesthetic/odor issue. | Mostly nuisance (taste/odor, laxative effect at high sulfate |
| Arsenic | MCL 0.010 mg/L (10 µg/L). | MAC 0.010 mg/L (10 µg/L). | Health — chronic risk. Not a nuisance parameter. |
| Lead / copper | Lead action level 0.015 mg/L (15 µg/L) in public systems under the Lead and Copp… | Lead MAC 0.005 mg/L (5 µg/L). Copper AO 1.0 mg/L. | Lead is a serious health risk (especially children). Copper |
| Total dissolved solids (TDS) | SMCL 500 mg/L. | AO 500 mg/L. | Mostly aesthetic; investigate which ions make up the TDS. |
| Fluoride | MCL 4.0 mg/L; SMCL 2.0 mg/L. | MAC 1.5 mg/L. | Health at high levels; staining of teeth is an early sign in |
| Uranium / radon | Uranium MCL 0.030 mg/L (30 µg/L). No federal MCL for radon in drinking water for… | Uranium MAC 0.02 mg/L (20 µg/L). Radon is addressed mainly via indoor-air guidan… | Health (kidney risk for uranium; lung cancer risk pathway fo |
| Chloride / sodium | Chloride SMCL 250 mg/L. Sodium has a drinking-water advisory for people on very … | Chloride AO 250 mg/L. Sodium AO 200 mg/L. | Mostly taste/corrosion; sodium matters for some medical diet |
Total coliform & E. coli
De quoi s'agit-il : Coliform bacteria are indicators. Total coliforms can come from the environment; E. coli points to fecal contamination and a higher chance of pathogens.
EPA (É.-U.) : E. coli MCL is a treatment technique goal of zero (none present). A positive total-coliform or E. coli result on a private well means do not drink untreated water until you retest and fix the cause.
Santé Canada : E. coli MAC: none detectable per 100 mL. Total coliforms are used as an operational/indicator parameter; detection warrants investigation.
Santé ou nuisance : Health risk when E. coli (or enterococci) is present. Total coliform alone is a warning about well integrity, not always an immediate illness signal.
Quoi faire : Stop drinking the water (use bottled or boiled water for drinking/cooking if advice says boil works for bacteria). Shock-chlorinate the well after fixing sanitary defects, then retest with a certified lab (often 1 week and again ~4 weeks later). Call your health department if E. coli is confirmed.
Nitrate / nitrite
De quoi s'agit-il : Forms of nitrogen from fertilizer, manure, septic systems, and natural soil processes. Dangerous for infants (methemoglobinemia / 'blue baby' risk).
EPA (É.-U.) : Nitrate MCL 10 mg/L as nitrogen. Nitrite MCL 1 mg/L as nitrogen.
Santé Canada : Nitrate MAC 10 mg/L as nitrate-nitrogen (45 mg/L as nitrate). Nitrite MAC 1 mg/L as nitrite-nitrogen.
Santé ou nuisance : Health — especially infants under 6 months and pregnant people. No reliable taste/smell warning.
Quoi faire : Do not boil (boiling concentrates nitrate). Use bottled water for infant formula if above the standard. Retest to confirm. Treatment options include anion exchange, reverse osmosis, or distillation at the tap — choose NSF/ANSI-certified gear for nitrate reduction and retest after install.
Iron
De quoi s'agit-il : Common in groundwater. Causes rusty stains, metallic taste, and orange water.
EPA (É.-U.) : Secondary MCL (SMCL) 0.3 mg/L (aesthetic).
Santé Canada : Aesthetic objective (AO) 0.3 mg/L.
Santé ou nuisance : Mostly nuisance (stains, taste). Very high levels can affect plumbing and appliances.
Quoi faire : Confirm with a lab (dissolved vs. total iron matters). Treatment often includes oxidation + filtration, water softeners for low ferrous iron, or specialized iron filters. Retest after treatment.
Manganese
De quoi s'agit-il : Natural mineral. Black/brown stains, bitter taste; also a health concern for infants at higher levels.
EPA (É.-U.) : SMCL 0.05 mg/L (aesthetic). EPA has also issued a health advisory for bottle-fed infants.
Santé Canada : MAC 0.12 mg/L; AO 0.02 mg/L.
Santé ou nuisance : Both — stains at low levels; health MAC protects bottle-fed infants.
Quoi faire : Use another water source for infant formula if above health guidance. Treatment: oxidation/filtration, water softener (limited), or RO for drinking water. Retest after install.
Hardness (calcium & magnesium)
De quoi s'agit-il : Dissolved calcium and magnesium. Causes scale, soap scum, and dry skin/hair complaints.
EPA (É.-U.) : No MCL. Often expressed as mg/L as CaCO3; 'hard' water commonly starts around 120 mg/L.
Santé Canada : No health-based MAC; aesthetic/operational issue.
Santé ou nuisance : Nuisance / plumbing — not usually a health MCL issue.
Quoi faire : Water softener (ion exchange) is the usual whole-house fix. Keep a separate unsoftened tap for drinking if you prefer, and maintain salt/resin as directed.
pH
De quoi s'agit-il : How acidic or basic the water is. Low pH can corrode pipes and pull metals into water; high pH can cause scale and taste issues.
EPA (É.-U.) : SMCL range typically 6.5–8.5.
Santé Canada : Aesthetic objective generally 7.0–10.5 for treated distribution systems; private wells still use pH as a corrosion/operational clue.
Santé ou nuisance : Indirect health risk via metals (lead/copper) when corrosive.
Quoi faire : If pH is low and metals are high, fix corrosion (neutralizing filter, etc.) and retest lead/copper. Work with a treatment pro and a certified lab.
Sulfate / hydrogen sulfide
De quoi s'agit-il : Sulfate is a dissolved mineral; hydrogen sulfide (H2S) is the 'rotten egg' gas from bacteria or reactions in the well/plumbing.
EPA (É.-U.) : Sulfate SMCL 250 mg/L. No federal MCL for H2S (odor-driven).
Santé Canada : Sulfate AO 500 mg/L. H2S is primarily an aesthetic/odor issue.
Santé ou nuisance : Mostly nuisance (taste/odor, laxative effect at high sulfate). Investigate bacterial sulfate reduction if odor is strong.
Quoi faire : For H2S: shock chlorination, aeration, oxidizing filters, or activated carbon depending on level. For high sulfate: RO or anion exchange for drinking water. Retest after treatment.
Arsenic
De quoi s'agit-il : Naturally occurring in some bedrock aquifers. No taste or smell. Long-term exposure raises cancer and other health risks.
EPA (É.-U.) : MCL 0.010 mg/L (10 µg/L).
Santé Canada : MAC 0.010 mg/L (10 µg/L).
Santé ou nuisance : Health — chronic risk. Not a nuisance parameter.
Quoi faire : Do not boil. Use bottled water for drinking/cooking until treated. Point-of-use RO, adsorptive media, or anion exchange systems certified for arsenic reduction; retest treated water yearly.
Lead / copper
De quoi s'agit-il : Usually from plumbing, pumps, or fixtures — especially with corrosive water — not from the aquifer itself.
EPA (É.-U.) : Lead action level 0.015 mg/L (15 µg/L) in public systems under the Lead and Copper Rule; goal is zero. Copper action level 1.3 mg/L.
Santé Canada : Lead MAC 0.005 mg/L (5 µg/L). Copper AO 1.0 mg/L.
Santé ou nuisance : Lead is a serious health risk (especially children). Copper can cause stomach upset and blue-green stains.
Quoi faire : Use a first-draw sample as the lab instructs. Flush taps before drinking if advised. Replace leaded components; consider certified NSF/ANSI 53 filters for lead. Fix corrosive pH. Retest after changes.
Total dissolved solids (TDS)
De quoi s'agit-il : Sum of dissolved minerals. High TDS tastes salty or mineral-heavy and can stress plumbing and treatment gear.
EPA (É.-U.) : SMCL 500 mg/L.
Santé Canada : AO 500 mg/L.
Santé ou nuisance : Mostly aesthetic; investigate which ions make up the TDS.
Quoi faire : Look at the full panel (sodium, chloride, hardness, sulfate). RO reduces TDS at the tap. Softening alone does not remove all TDS.
Fluoride
De quoi s'agit-il : Can be natural in groundwater. Protects teeth at low levels; excess risks dental/skeletal fluorosis.
EPA (É.-U.) : MCL 4.0 mg/L; SMCL 2.0 mg/L.
Santé Canada : MAC 1.5 mg/L.
Santé ou nuisance : Health at high levels; staining of teeth is an early sign in children.
Quoi faire : If above guidance, use an alternate drinking source for kids and consider RO or activated alumina systems rated for fluoride. Retest yearly if treating.
Uranium / radon
De quoi s'agit-il : Naturally occurring radioactive elements in some bedrock. Uranium is a dissolved metal; radon is a gas that can move from water into indoor air when taps run.
EPA (É.-U.) : Uranium MCL 0.030 mg/L (30 µg/L). No federal MCL for radon in drinking water for private wells; EPA has proposed/guidance levels historically discussed around 300–4,000 pCi/L depending on context — confirm with your state lab and health department.
Santé Canada : Uranium MAC 0.02 mg/L (20 µg/L). Radon is addressed mainly via indoor-air guidance; ask provincial labs about water radon testing where available.
Santé ou nuisance : Health (kidney risk for uranium; lung cancer risk pathway for radon via air).
Quoi faire : Test with an accredited lab experienced in radionuclides. Uranium: RO or anion exchange. Radon in water: aeration treatment; also test indoor air. Do not rely on boiling.
Chloride / sodium
De quoi s'agit-il : Salt-related ions from road salt, water softeners, seawater intrusion, or geology. Taste and corrosion clues.
EPA (É.-U.) : Chloride SMCL 250 mg/L. Sodium has a drinking-water advisory for people on very low-sodium diets (often discussed near 20 mg/L for that population) — not a formal MCL.
Santé Canada : Chloride AO 250 mg/L. Sodium AO 200 mg/L.
Santé ou nuisance : Mostly taste/corrosion; sodium matters for some medical diets.
Quoi faire : If you soften water, keep a hard-water tap for drinking/cooking. RO reduces sodium/chloride at the tap. Investigate softener settings and nearby salt sources. People on sodium-restricted diets should ask their clinician.
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Avis : Cette page est informative, pas un avis médical ou juridique. Les méthodes et unités varient. Comparez votre rapport aux chiffres imprimés dessus, et consultez un laboratoire accrédité ou votre direction de santé publique avant de changer de traitement ou d'habitudes. Si quelqu'un est malade, contactez un clinicien.