Lab report checker
Check your well water test results against EPA limits
Plain comparison, not household advice. Choose a report entry to see the published EPA values, what kind of reference each is, and the numerical relationship. Ask your laboratory about the report and your state or local health department what it means for your household.
Built from the linked EPA documents and CDC guidance. We have not tested your water. This page compares entries, not water samples.
Standards, local geology and state requirements all vary. Confirm anything on this page with your state or local health department before acting on it.
Read how to read well water test results for an example report and explanations of its fields.
Place an entry beside the references
EPA does not regulate private wells. The references below are not a determination for your household.
Enter one report line at a time. Match the analyte and unit exactly. This tool does not read or upload a report.
If the controls stay unavailable, the checker script did not load. Use the full EPA table below instead.
These results compare your numbers with published EPA values. They are not a safety verdict on your water.
The lab report checker runs in your browser. Numbers you type into it are not sent to us, saved or recorded. Google Analytics is not loaded on this checker. Entries disappear when you clear them, reload or leave this page.
Questions to take to your lab or health department
Keep the complete report with you, including its units, qualifiers and sample information.
- What exactly does this analyte name mean on my report, and what unit and reporting basis did you use?
- For ND or a less-than result, what method and detection or reporting limit apply?
- Do the sample collection, handling and timing affect how this result can be used?
- Is another sample needed? If so, what collection instructions should the receiving laboratory provide?
- Which state or local requirements and reference values apply, and who can explain the result for my household?
Contact the laboratory named on your report and your state or local health department. The EPA state private-well program directory is a starting point for finding a state program, not a verified local department contact. CDC guidance for private well owners also identifies health departments as a source of advice.
Sources checked September 27, 2026.
Keep the unit and qualifier with the number
ND is not zero. It indicates not detected under the laboratory's method or reporting convention. Without the applicable detection or reporting limit, a numeric relationship cannot be determined. Ask the laboratory to explain its own notation.
A less-than entry is a bound. The reported concentration is below the typed bound, not equal to it. If that bound is at or below a reference, the entry is lower than that reference. If the bound is above it, the relationship cannot be determined from the entry alone.
For dilute water, mg/L is approximately ppm and ug/L is approximately ppb. The physical-unit relationship is 1 mg/L = 1,000 ug/L. Keep nitrate as N separate from nitrate as NO3. EPA gives the rounded conversion factor 4.4: 10 mg/L as N is about 44 mg/L as NO3. Any comparison using that conversion is labeled approximate; it is not a separate EPA standard. Nitrite comparisons here require as N. Combined nitrate/nitrite is not included.
EPA's IRIS nitrate summary gives the explicit conversion “1 mg nitrate-nitrogen = 4.4 mg nitrate,” but its surrounding sentence says “nitrite molecule.” That source-wording discrepancy is retained here, not silently corrected. This checker uses the explicit nitrate parenthesis only as a rounded equivalence, not another standard.
Bacteria remain Present or Absent. Neither is converted into a numeric concentration. The accepted EPA sources provide no hardness comparison value; absence of a comparator is not zero.
Sources: EPA S01; EPA IRIS nitrate conversion; EPA nitrate reporting basis; EPA UCMR units and reporting; EPA UCMR reporting limits; EPA ECHO qualifier examples; EPA secondary references. Definitions follow the EPA source register below; they do not replace a named laboratory's report legend.
Sources checked September 27, 2026.
Full EPA reference table
All accepted reference types remain separate. Read each purpose and condition with its value. Public-system action levels, sampling rules and health goals are not one-sample private-well compliance tests. The dated lead transition and manganese exposure conditions are retained, not selected for a household.
Sources checked September 27, 2026.
| Contaminant and other names | EPA value and type | Purpose and conditions | Sources |
|---|---|---|---|
| Total coliform Total coliforms; total coliform bacteria | No numerical value Presence / absence Not applicable: treatment technique (RTCR treatment technique, not a numeric MCL or current MCLG) | EPA uses total-coliform results in public-system monitoring and assessment requirements, not as a numerical private-well limit. RTCR replaced the previous total-coliform MCL and MCLG; EPA's general table still shows the older zero goal and 5.0% sample formulation. Do not use either as the current RTCR value. Keep bacterial results qualitative. | EPA S03 · EPA S04 · EPA S05 |
| E. coli Escherichia coli | 0 Qualitative goal of zero, not mg/L health goal (MCLG) | This is EPA's non-enforceable E. coli health goal, separate from its public-system compliance rule. Do not relabel zero as an MCL or convert it to CFU/MPN. EPA's RTCR methods specify presence/absence; the 100 mL sample volume is not a private-well numerical cutoff. | EPA S03 · EPA S05 |
| E. coli Escherichia coli | Rule-defined routine/repeat-sample conditions Presence / absence and sampling conditions enforceable limit for public systems (RTCR E. coli MCL, not a single numerical threshold) | EPA's E. coli MCL is a public-system rule based on routine and repeat samples and specified sampling or analysis failures. Conditions include an E. coli-positive repeat after a total-coliform-positive routine sample; a total-coliform-positive repeat after an E. coli-positive routine; missing required repeats after an E. coli-positive routine; or failure to test a total-coliform-positive repeat for E. coli. None is a one-sample private-well compliance test. | EPA S03 · EPA S04 |
| Nitrate Nitrate-N; nitrate nitrogen; NO3-N (as N); nitrate as NO3 is a different reporting basis | 10 mg/L as N enforceable limit for public systems (MCL) | This is EPA's enforceable nitrate concentration standard for public water systems. Public-system concentration standard, not a compliance determination from one private-well sample. Confirm the basis: 10 mg/L as N is about 44 mg/L as NO3, using EPA's rounded 4.4 conversion; it is not a separate EPA standard. Do not map combined nitrate/nitrite to nitrate alone. | EPA S01 |
| Nitrate Nitrate-N; nitrate nitrogen; NO3-N (as N); nitrate as NO3 is a different reporting basis | 10 mg/L as N health goal (MCLG) | This is EPA's non-enforceable nitrate health goal, kept separate from its enforceable standard. A health goal is not an enforceable limit or a verdict on a household result. | EPA S01 |
| Nitrite Nitrite-N; nitrite measured as nitrogen (as N) | 1 mg/L as N enforceable limit for public systems (MCL) | This is EPA's enforceable nitrite concentration standard for public water systems. Public-system concentration standard, not a compliance determination from one private-well sample. The value is measured as nitrogen. Nitrite as NO2 is a different basis; the nitrate conversion factor must not be reused. | EPA S01 |
| Nitrite Nitrite-N; nitrite measured as nitrogen (as N) | 1 mg/L as N health goal (MCLG) | This is EPA's non-enforceable nitrite health goal, kept separate from its enforceable standard. A health goal is not an enforceable limit or a verdict on a household result. | EPA S01 |
| Arsenic As | 0.010 mg/L enforceable limit for public systems (MCL) | This is EPA's enforceable arsenic concentration standard for public water systems. Public-system concentration standard, not a compliance determination from one private-well sample. | EPA S01 |
| Arsenic As | 0 mg/L health goal (MCLG) | This is EPA's non-enforceable arsenic health goal, kept separate from its enforceable standard. A health goal is not an enforceable limit or a verdict on a household result. | EPA S01 |
| Lead Pb | 0.015 mg/L action level (Lead and Copper Rule action level) Timing: Before November 1, 2027. | EPA uses this lead action level with a public water system's 90th-percentile tap-sampling result, not as a numeric MCL. Lead has an action level, not an MCL. A single private-well result does not establish a public-system action-level exceedance. The future date is the LCRI compliance date, not its announcement date. | EPA S01 · EPA S21 |
| Lead Pb | 0.010 mg/L action level (Lead and Copper Rule action level) Timing: From November 1, 2027. | EPA uses this lead action level with a public water system's 90th-percentile tap-sampling result, not as a numeric MCL. Lead has an action level, not an MCL. A single private-well result does not establish a public-system action-level exceedance. The future date is the LCRI compliance date, not its announcement date. | EPA S01 · EPA S21 |
| Lead Pb | 0 mg/L health goal (MCLG) | EPA's non-enforceable lead health goal is zero, distinct from both dated action levels. A zero health goal is not the action level or a zero-detection claim. | EPA S01 |
| Copper Cu | 1.3 mg/L action level (Lead and Copper Rule action level) | EPA uses this copper action level with a public water system's 90th-percentile tap-sampling result, not as a numeric MCL. Keep separate from the 1.0 mg/L secondary guideline and the separate 1.3 mg/L health goal. | EPA S01 · EPA S21 |
| Copper Cu | 1.3 mg/L health goal (MCLG) | This is EPA's non-enforceable copper health goal, even though it has the same numerical value as the action level. Matching numbers do not make a health goal and an action level the same kind of value. | EPA S01 |
| Copper Cu | 1.0 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses metallic taste and blue-green staining. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. | EPA S02 |
| Fluoride No additional EPA-verified alias added | 4.0 mg/L enforceable limit for public systems (MCL) | This is EPA's enforceable fluoride concentration standard for public water systems. Public-system concentration standard, not a compliance determination from one private-well sample. | EPA S01 |
| Fluoride No additional EPA-verified alias added | 4.0 mg/L health goal (MCLG) | This is EPA's non-enforceable fluoride health goal, kept separate from its enforceable standard. A health goal is not an enforceable limit or a verdict on a household result. | EPA S01 |
| Fluoride No additional EPA-verified alias added | 2.0 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses tooth discoloration. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. EPA separately requires notice by community water systems above 2.0 mg/L but not above 4.0 mg/L within 12 months of learning of the exceedance. This is public-system context, not a private-well instruction. | EPA S02 |
| Uranium U | 30 ug/L enforceable limit for public systems (MCL) | This is EPA's enforceable uranium concentration standard for public water systems. Public-system concentration standard, not a compliance determination from one private-well sample. This is a mass concentration in ug/L, not an activity value in pCi/L. No mass/activity conversion is supplied. | EPA S01 |
| Uranium U | 0 ug/L health goal (MCLG) | This is EPA's non-enforceable uranium health goal, kept separate from its enforceable standard. A health goal is not an enforceable limit or a verdict on a household result. | EPA S01 |
| Manganese Mn | 0.05 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses color, staining and taste. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. Separate EPA health advisories also exist; this is not the sole manganese reference. | EPA S02 |
| Manganese Mn | 0.3 mg/L non-enforceable guideline (Lifetime health advisory) | This is EPA's nonregulatory manganese advisory for lifetime exposure. EPA summary-table basis: 70-kg adult, 2 L/day. EPA specifically says to use its lifetime value of 0.3 mg/L even for an acute exposure of 10 days in infants younger than 6 months. This is an attributed source condition, not a new household recommendation. No exposure or age is selected for the reader; route household interpretation to the health department. | EPA S06 · EPA S07 · EPA S08 |
| Manganese Mn | 1 mg/L non-enforceable guideline (One-day health advisory) | EPA uses the child ten-day advisory as a conservative estimate for a one-day manganese exposure. EPA says no suitable information was available to derive a separate one-day value. It uses the child ten-day value for children and adults. EPA specifically says to use its lifetime value of 0.3 mg/L even for an acute exposure of 10 days in infants younger than 6 months. This is an attributed source condition, not a new household recommendation. No exposure or age is selected for the reader; route household interpretation to the health department. | EPA S06 · EPA S07 · EPA S08 |
| Manganese Mn | 1 mg/L non-enforceable guideline (Ten-day health advisory) | This is EPA's nonregulatory manganese advisory for a ten-day exposure, with the document's infant condition retained. EPA derivation uses a 10-kg child and at most 1 liter of formula per day. EPA specifically says to use its lifetime value of 0.3 mg/L even for an acute exposure of 10 days in infants younger than 6 months. This is an attributed source condition, not a new household recommendation. No exposure or age is selected for the reader; route household interpretation to the health department. | EPA S06 · EPA S07 · EPA S08 |
| Iron Fe | 0.3 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses color, sediment, taste and staining. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. | EPA S02 |
| pH pH; no additional EPA-verified alias added | 6.5 to 8.5 pH units non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses taste, corrosion and deposits. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. This is a range, not a one-sided concentration limit. Do not convert pH to mg/L, ppm, ug/L or ppb. | EPA S02 |
| Sulfate No additional EPA-verified alias added | 250 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses taste. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. | EPA S02 |
| Chloride No additional EPA-verified alias added | 250 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses taste. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. | EPA S02 |
| Total dissolved solids TDS | 500 mg/L non-enforceable guideline (Secondary maximum contaminant level (SMCL)) | EPA's secondary guideline addresses deposits, color, staining and taste. Not federally enforceable as an SMCL; states may adopt enforceable standards. Do not turn the stated purpose into reassurance. TDS is not hardness. Do not apply this number to hardness. | EPA S02 |
| Hardness Total hardness; Hardness, Total | No EPA value listed mg/L as CaCO3 (reported measurement, not a limit) Not applicable: no EPA value (No federal EPA comparator in inspected tables) | The checked EPA drinking-water tables do not list a comparison value for hardness. No numerical comparator, not zero. Do not borrow the TDS guideline or invent soft/hard cutoffs. The unit and aliases come from EPA Method 130.1; other report units must remain as reported. State/local or other-purpose criteria are not evaluated. | EPA S01 · EPA S02 · EPA S07 · EPA S19 |
Sources opened for this page
Sources checked September 27, 2026.
The EPA entries are the primary sources for the reference table and unit/qualifier notes. CDC is linked for private-well guidance. EPA's state directory is a contact starting point. No commercial or affiliate links are included.
- EPA S01: National Primary Drinking Water Regulationshttps://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
- EPA S02: Secondary Drinking Water Standards: Guidance for Nuisance Chemicalshttps://www.epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals
- EPA S03: Revised Total Coliform Rule And Total Coliform Rulehttps://www.epa.gov/dwreginfo/revised-total-coliform-rule-and-total-coliform-rule
- EPA S04: A Revised Total Coliform Rule Guide for Small Public Water Systems (October 2015)https://www.epa.gov/sites/default/files/2015-11/documents/rtcr_small_pws_guide_epa815b15002_oct2015_508compliant.pdf
- EPA S05: RTCR approved analytical methods (January 2024)https://www.epa.gov/system/files/documents/2024-02/rtcr-methods-table.pdf
- EPA S10: IRIS Nitrate Chemical Assessment Summary, conversion footnotehttps://iris.epa.gov/static/pdfs/0076_summary.pdf
- EPA S11: Fifth Unregulated Contaminant Monitoring Rule Data Finderhttps://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule-data-finder
- EPA S12: UCMR 5 Data Summary (July 2026)https://www.epa.gov/system/files/documents/2023-08/ucmr5-data-summary_0.pdf
- EPA S13: Water Pollutant Loading Tool FAQ, qualified resultshttps://echo.epa.gov/trends/loading-tool/resources/faq
- EPA S14: Private Drinking Water Wellshttps://www.epa.gov/privatewells
- EPA S15: Protect Your Home's Waterhttps://www.epa.gov/privatewells/protect-your-homes-water
- EPA S06: Drinking Water Health Advisory for Manganese (January 2004)https://www.epa.gov/sites/default/files/2014-09/documents/support_cc1_magnese_dwreport_0.pdf
- EPA S07: Drinking Water Standards and Health Advisories (March 2018)https://www.epa.gov/system/files/documents/2022-01/dwtable2018.pdf
- EPA S08: Drinking Water Health Advisories, current EPA indexhttps://www.epa.gov/sdwa/drinking-water-health-advisories-has
- EPA S09: EPA manganese supporting-documents indexhttps://www.epa.gov/ccl/regulatory-determination-1-support-documents-manganese
- EPA S19: EPA Method 130.1, Hardness, Totalhttps://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P1017QGI.txt
- EPA S16: EPA Method 200.8, metals and trace elementshttps://www.epa.gov/sites/default/files/2015-06/documents/epa-200.8.pdf
- EPA S17: EPA Method 200.7, metals and trace elementshttps://www.epa.gov/sites/default/files/2015-08/documents/method_200-7_rev_4-4_1994.pdf
- EPA S18: EPA Method 300.0, inorganic anionshttps://www.epa.gov/sites/default/files/2015-08/documents/method_300-0_rev_2-1_1993.pdf
- EPA S20: EPA archived volunteer monitoring manual, nitrate terminology onlyhttps://archive.epa.gov/water/archive/web/html/vms57.html
- EPA S21: EPA lead and copper reporting: the 90th percentilehttps://www.epa.gov/lead/i-am-looking-water-report-my-public-water-system-under-contaminant-heading-lead-and-copper
- CDC: guidance for private well ownershttps://www.cdc.gov/drinking-water/safety/index.html
- EPA: state private-well programshttps://www.epa.gov/privatewells/private-drinking-water-well-programs-your-state