Standards Hub
Environmental lab accreditation, state by state.
Who accredits your lab, which standard they assess against, and what auditors look for in your initial calibrations. Plain language, linked to primary sources, updated as the standards change.
State finder
Find your state’s accreditation program.
Select a state to see who accredits environmental labs there, or filter by program type. Every entry links to its source.
| State | Program type | Agency and program | Scope and reciprocity | Source |
|---|---|---|---|---|
| Alabama | Drinking water certification only | Alabama Department of Environmental Management ADEM laboratory certification |
Certification required for labs submitting Safe Drinking Water Act compliance data; out-of-state labs certified based on home-state certification. TNI directory lists ADEM as not recognizing NELAP directly. | Source for Alabama (opens in a new tab) |
| Alaska | State program (non-NELAP) | Alaska Department of Environmental Conservation Drinking Water lab certification; Contaminated Sites lab approval |
Two programs: drinking water certification (out-of-state labs reviewed using home-state audits) and a Contaminated Sites approval limited to labs running Alaska methods AK101-AK103, which accepts NELAP or non-governmental (ISO 17025) accreditation. | Source for Alaska (opens in a new tab) |
| Arizona | State program (non-NELAP) | Arizona Department of Health Services Environmental laboratory licensure |
State licensing of labs producing compliance data (drinking water, wastewater, hazardous waste and other matrices); TNI directory lists no recognition of NELAP and no reciprocity agreements, so out-of-state labs need an Arizona license. | Source for Arizona (opens in a new tab) |
| Arkansas | State program (non-NELAP) | Arkansas Division of Environmental Quality (non-drinking water); Arkansas Department of Health (drinking water) ADEQ environmental laboratory certification; ADH drinking water lab certification |
ADEQ certifies labs for non-drinking water compliance data and recognizes NELAP accreditation in lieu of an on-site visit. ADH certifies drinking water labs (public health lab and in-state public water system labs). | Source for Arkansas (opens in a new tab) |
| California | State program (non-NELAP) | State Water Resources Control Board, Division of Drinking Water Environmental Laboratory Accreditation Program (ELAP) |
Accreditation required for environmental samples analyzed for regulatory purposes (drinking water, wastewater, hazardous waste and more). ELAP requires the 2016 TNI standard (full compliance by Jan 1, 2024); out-of-state labs may apply by reciprocity based on primary accreditation from another state or a TNI-recognized non-governmental AB. | Source for California (opens in a new tab) |
| Colorado | Drinking water certification only | Colorado Department of Public Health and Environment Drinking water laboratory certification |
Certification required for labs testing Colorado public drinking water; TNI directory lists no NELAP recognition or reciprocity agreements. | Source for Colorado (opens in a new tab) |
| Connecticut | State program (non-NELAP) | Connecticut Department of Public Health Environmental Laboratory Certification Program (ELCP) |
Required for all environmental labs testing Connecticut environmental samples (drinking water, wastewater, solid waste and others); recognizes NELAP accreditation and has reciprocity with states, NELAP and DoD. | Source for Connecticut (opens in a new tab) |
| Delaware | Drinking water certification only | Delaware Health and Social Services, Office of Drinking Water Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; recognizes NELAP accreditation for reciprocal certification. | Source for Delaware (opens in a new tab) |
| District of Columbia | EPA region certifies | U.S. EPA Region 3 (Laboratory Services and Applied Science Division) EPA Region 3 drinking water laboratory certification |
DC has no environmental laboratory accreditation program of its own; drinking water lab certification is handled by EPA Region 3. No separate DC program for other matrices was found. | Source for District of Columbia (opens in a new tab) |
| Florida | NELAP accreditation body | Florida Department of Health NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. Florida DOH accredits labs for drinking water, non-potable water, solid and chemical materials, and other matrices. | Source for Florida (opens in a new tab) |
| Georgia | State program (non-NELAP) | Georgia Department of Natural Resources, Environmental Protection Division EPD laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; recognizes NELAP accreditation and has reciprocity with primacy states, NELAP, A2LA and EPA. | Source for Georgia (opens in a new tab) |
| Hawaii | Drinking water certification only | Hawaii Department of Health Drinking water laboratory certification |
Required for labs doing EPA-mandated regulatory monitoring of Hawaii drinking water; NELAP certification accepted for out-of-state chemistry labs. | Source for Hawaii (opens in a new tab) |
| Idaho | Drinking water certification only | Idaho Department of Health and Welfare, Bureau of Laboratories Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act data; out-of-state labs accepted if they hold TNI accreditation or drinking water certification in their home state. | Source for Idaho (opens in a new tab) |
| Illinois | NELAP accreditation body | Illinois Environmental Protection Agency NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. Illinois EPA covers chemistry; the Illinois Department of Public Health separately certifies drinking water microbiology labs (not NELAP). | Source for Illinois (opens in a new tab) |
| Indiana | Drinking water certification only | Indiana Department of Health Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data (plus pool and spa testing); reciprocal certification for out-of-state labs with home-state drinking water certification. | Source for Indiana (opens in a new tab) |
| Iowa | State program (non-NELAP) | Iowa Department of Natural Resources Laboratory certification |
Required for any lab submitting environmental compliance data in Iowa, including drinking water, wastewater, underground storage tank and contaminated site/solid waste data; accepts NELAP or state-program certification by reciprocity. | Source for Iowa (opens in a new tab) |
| Kansas | NELAP accreditation body | Kansas Department of Health and Environment NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. TNI lists Kansas as the only AB still requiring the 2009 TNI standard rather than the 2016 version. | Source for Kansas (opens in a new tab) |
| Kentucky | State program (non-NELAP) | Kentucky Energy and Environment Cabinet, Department for Environmental Protection, Division of Water Kentucky Drinking Water Laboratory Certification Program (KDWLCP) and Kentucky Wastewater Laboratory Certification Program (KWLCP) |
Separate drinking water (SDWA) and wastewater (CWA, 401 KAR 5:320) certification programs. Does not formally recognize NELAP, but grants equivalency certification to labs certified by a comparable program. | Source for Kentucky (opens in a new tab) |
| Louisiana | NELAP accreditation body | Louisiana Department of Environmental Quality NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. LDEQ accredits environmental labs; the Louisiana Department of Health separately certifies drinking water labs. | Source for Louisiana (opens in a new tab) |
| Maine | State program (non-NELAP) | Maine Department of Health and Human Services Maine laboratory certification |
Required for all labs analyzing samples under the Safe Drinking Water Act, Clean Water Act, RCRA and leaking underground storage tank rules; does not recognize NELAP directly but accepts equivalent state or federal certification. | Source for Maine (opens in a new tab) |
| Maryland | Drinking water certification only | Maryland Department of the Environment Water quality laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; reciprocity for labs certified by another state, NELAP or an EPA region with supporting PT and QA documents. | Source for Maryland (opens in a new tab) |
| Massachusetts | State program (non-NELAP) | Massachusetts Department of Environmental Protection Laboratory certification program |
Certifies labs for drinking water (required for SDWA data) and non-potable water under Clean Water Act methods; recognizes NELAP and resident-state or EPA certification by reciprocity. | Source for Massachusetts (opens in a new tab) |
| Michigan | Drinking water certification only | Michigan Department of Environment, Great Lakes, and Energy (EGLE) Drinking water laboratory certification |
Required for all labs testing Michigan drinking water for regulatory compliance; does not recognize NELAP directly but accepts EPA certification or equivalent state certification. | Source for Michigan (opens in a new tab) |
| Minnesota | NELAP accreditation body | Minnesota Department of Health NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for Minnesota (opens in a new tab) |
| Mississippi | Drinking water certification only | Mississippi State Department of Health, Public Health Laboratory Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; accepts EPA or equivalent state certification, or NELAP accreditation specific to drinking water. | Source for Mississippi (opens in a new tab) |
| Missouri | Drinking water certification only | Missouri Department of Natural Resources Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; reciprocity for EPA-certified or NELAP-accredited labs. | Source for Missouri (opens in a new tab) |
| Montana | Drinking water certification only | Montana Department of Public Health and Human Services Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; out-of-state labs accepted with NELAP, EPA or home-state accreditation. | Source for Montana (opens in a new tab) |
| Nebraska | Drinking water certification only | Nebraska Department of Health and Human Services Drinking water laboratory certification (Title 179) |
Required for labs submitting Nebraska Safe Drinking Water Act compliance data; certification granted to labs holding accreditation from a national AB or an EPA-certified state program. | Source for Nebraska (opens in a new tab) |
| Nevada | State program (non-NELAP) | Nevada Division of Environmental Protection Laboratory Certification Program |
Certification required for data submitted under drinking water, wastewater (water pollution control), corrective action/cleanup, waste management and mining programs. Out-of-state assessments are accepted case by case; there are no formal reciprocity agreements, so out-of-state labs still need Nevada certification. | Source for Nevada (opens in a new tab) |
| New Hampshire | NELAP accreditation body | New Hampshire Department of Environmental Services NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for New Hampshire (opens in a new tab) |
| New Jersey | NELAP accreditation body | New Jersey Department of Environmental Protection NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for New Jersey (opens in a new tab) |
| New Mexico | Drinking water certification only | New Mexico Environment Department, Drinking Water Bureau Drinking Water Laboratory Certification Program (DWLCP) |
Required for labs submitting Safe Drinking Water Act compliance data; certifies by reciprocity labs holding EPA or NELAP certification. | Source for New Mexico (opens in a new tab) |
| New York | NELAP accreditation body | New York State Department of Health (Wadsworth Center ELAP) NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. NY ELAP certifies labs for potable water, non-potable water, solid and hazardous waste, and air. | Source for New York (opens in a new tab) |
| North Carolina | State program (non-NELAP) | NC Department of Health and Human Services, State Laboratory of Public Health (drinking water); NC Department of Environmental Quality (wastewater/other) Drinking water lab certification; DEQ laboratory certification |
State Laboratory of Public Health certifies drinking water labs (recognizes NELAP, generally home-state reciprocity). DEQ certifies labs for Clean Water Act and other DEQ compliance data, with no formal reciprocity but possible waiver of the initial on-site assessment. | Source for North Carolina (opens in a new tab) |
| North Dakota | State program (non-NELAP) | North Dakota Department of Environmental Quality (chemistry); Department of Health and Human Services (microbiology) North Dakota Environmental Laboratory Certification Program |
Required for labs submitting data under the Safe Drinking Water Act, Clean Water Act, and state programs including hazardous waste; recognizes NELAP and other recognized primary certificates. | Source for North Dakota (opens in a new tab) |
| Ohio | Drinking water certification only | Ohio Environmental Protection Agency, Division of Environmental Services Drinking water laboratory certification (OAC 3745-89) |
Ohio EPA certifies labs analyzing public drinking water (OAC rule 3745-89-03). Ohio’s Voluntary Action Program lab certification was being wound down in 2023 in favor of accepting TNI-accredited labs (per TNI); Ohio is not a NELAP AB. | Source for Ohio (opens in a new tab) |
| Oklahoma | NELAP accreditation body | Oklahoma Department of Environmental Quality NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for Oklahoma (opens in a new tab) |
| Oregon | NELAP accreditation body | Oregon Health Authority (ORELAP) NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for Oregon (opens in a new tab) |
| Pennsylvania | NELAP accreditation body | Pennsylvania Department of Environmental Protection NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for Pennsylvania (opens in a new tab) |
| Rhode Island | State program (non-NELAP) | Rhode Island Department of Health Environmental laboratory certification |
Required for labs testing water under the Safe Drinking Water Act or Clean Water Act and for environmental lead testing; recognizes home-state and NELAP certification. | Source for Rhode Island (opens in a new tab) |
| South Carolina | State program (non-NELAP) | South Carolina Department of Environmental Services (formerly SCDHEC) Laboratory certification program |
Required for all labs whose compliance results are submitted to the department, across drinking water, wastewater and other programs. No formal reciprocity; out-of-state labs must first hold certification from an equivalent program. | Source for South Carolina (opens in a new tab) |
| South Dakota | Drinking water certification only | South Dakota Department of Agriculture and Natural Resources / State Health Laboratory Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data; accepts EPA certification or certification by the lab’s home state. | Source for South Dakota (opens in a new tab) |
| Tennessee | Drinking water certification only | Tennessee Department of Environment and Conservation, Division of Water Resources Drinking water laboratory certification |
Required for labs submitting public water system data for SDWA compliance; out-of-state labs may be certified by reciprocity with their home-state certification officers. | Source for Tennessee (opens in a new tab) |
| Texas | NELAP accreditation body | Texas Commission on Environmental Quality NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. TCEQ accreditation is required for most environmental data submitted to TCEQ. | Source for Texas (opens in a new tab) |
| Utah | NELAP accreditation body | Utah Department of Health and Human Services NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. | Source for Utah (opens in a new tab) |
| Vermont | Drinking water certification only | Vermont Department of Health Drinking water laboratory certification |
Required for labs submitting Safe Drinking Water Act compliance data and labs testing private drinking water; recognizes NELAP accreditation but has no reciprocity agreements. | Source for Vermont (opens in a new tab) |
| Virginia | NELAP accreditation body | Virginia Department of General Services, Division of Consolidated Laboratory Services NELAP-recognized environmental laboratory accreditation program (TNI standard) |
Accredits labs to the TNI standard across the fields of accreditation the agency offers, and grants secondary accreditation to labs accredited by other NELAP ABs. DCLS administers both the Virginia Environmental Laboratory Accreditation Program (NELAP) and drinking water certification. | Source for Virginia (opens in a new tab) |
| Washington | State program (non-NELAP) | Washington State Department of Ecology Environmental Laboratory Accreditation Program |
Ecology is the accrediting body for environmental and drinking water labs (drinking water, wastewater, surface and groundwater, stormwater, biosolids, tissue, soil, sediment, solid and aqueous waste). Recognizes NELAP and other primary accreditations case by case, without formal reciprocity agreements. | Source for Washington (opens in a new tab) |
| West Virginia | State program (non-NELAP) | West Virginia Department of Health, Office of Laboratory Services (drinking water); West Virginia Department of Environmental Protection (environmental) Drinking water lab certification; WVDEP laboratory certification |
Two programs covering state and federal compliance samples; neither recognizes NELAP directly, but both may accept labs certified by EPA or equivalent state programs. | Source for West Virginia (opens in a new tab) |
| Wisconsin | State program (non-NELAP) | Wisconsin Department of Natural Resources (chemistry); Department of Agriculture, Trade and Consumer Protection (microbiology) Laboratory certification and registration program (NR 149) |
Required for labs testing Wisconsin compliance samples for DNR programs under NR 149 (except asbestos and radiochemistry); does not recognize NELAP directly, reciprocity only where standards are similar and acceptance is mutual. | Source for Wisconsin (opens in a new tab) |
| Wyoming | EPA region certifies | U.S. EPA Region 8 EPA Region 8 drinking water laboratory certification |
Wyoming has no state drinking water primacy or lab certification program; EPA Region 8 certifies labs for SDWA compliance data, accepting state or NELAP-associated certification by reciprocity for approved methods. | Source for Wyoming (opens in a new tab) |
| Puerto Rico | Drinking water certification only | Puerto Rico Department of Health Laboratory certification program |
Certifies private labs on the island for microbiology, Cryptosporidium and chemistry (drinking water focus); recognizes NELAP, with reciprocity for Cryptosporidium, chemistry and radiochemistry but not microbiology. | Source for Puerto Rico (opens in a new tab) |
Last reviewed October 2026. Program details change, so confirm current requirements with the agency before you apply. Several entries rely on TNI’s program directory, which may lag agency updates.
The common thread
What every auditor checks in an initial calibration.
Programs differ in scope and paperwork. On calibration, they converge on the same questions.
Enough standards for the model
More complex models need more calibration levels. Auditors check that the number of standards supports the fit you chose.
A range that brackets your results
The lowest standard at or below the reporting limit, the highest at or above the top reported value, and anything outside the range qualified.
Relative error, not r² alone
TNI guidance notes that the correlation coefficient is not a measure of relative error. Low and mid-level accuracy is what auditors look for.
Records that rebuild the curve
Raw data, model and weighting choices, and verification results complete enough for an auditor to reconstruct every calibration.
National standards
The standards behind every program.
In force
TNI Environmental Laboratory Sector Standard (2016)
The 2016 TNI standard is the version NELAP accreditation bodies assess against. A revised chemistry module (EL-V1M4-2025) is in draft, and a quality management module rebuilt on ISO/IEC 17025:2017 reached voting draft in May 2026. Neither has been adopted yet.
What auditors look for: Enough standards for the model you chose, a range that brackets every reported result, acceptance judged by relative error at the low and mid levels rather than the correlation coefficient alone, defined calibration verification, and raw data that let an auditor rebuild the curve.
14 accreditation bodies
NELAP
NELAP is a mutual-recognition program, not a regulator. Each recognized state agency accredits labs to the TNI standard, is peer-evaluated by the others, and grants secondary accreditation to labs accredited elsewhere in the program.
What auditors look for: The TNI calibration clauses applied consistently: documented procedures in the SOP, a defensible model choice per analyte, relative-error-based ICAL acceptance, initial and continuing verification, and traceable records.
5th edition, Supplement 2
EPA Drinking Water Certification Manual
Primacy states, and EPA regions where there is no state program, certify labs for Safe Drinking Water Act compliance using this manual as the minimum criteria. EPA lists no sixth edition.
What auditors look for: Each approved method calibrated exactly as written: number of levels, acceptance limits and verification frequency. Drinking water methods are prescriptive, so a departure is a finding rather than a judgment call.
Revision 5, March 2018
SW-846 Method 8000D
The determinative chromatography method behind most RCRA and soil work. It is required where a regulation or permit names it, and it is referenced widely by state programs and the DoD/DOE QSM.
What auditors look for: Average response factor, linear, weighted and non-linear calibrations are all allowed, and the lab is expected to justify the choice. Auditors look for evidence that the model actually fits the low end, not just a high correlation.
rMUR 2 final; MUR 22 proposed
40 CFR Part 136 (Clean Water Act methods)
Part 136 methods are mandatory for NPDES compliance monitoring. The last final update was April 2024. A proposal to add Method 1633A for PFAS in wastewater has been pending since January 2025.
What auditors look for: Section 136.7 makes calibration one of 12 essential QC elements, covering the ICAL plus initial and continuing verification. Where a method is silent, the SOP must define calibration acceptance and verification frequency.
In force; deadline June 30, 2026
DoD/DOE QSM 6.0
The Consolidated Quality Systems Manual for labs doing Department of Defense and Department of Energy work. All DoD ELAP labs had to be accredited to QSM 6.0 by June 30, 2026.
What auditors look for: Method-specific calibration and QC tables layered on top of TNI and the EPA methods, often stricter than the base method. Second-source verification and documented model and weighting choices are common focus points.
In force
ISO/IEC 17025:2017
The competence standard behind third-party accreditation, including DoD ELAP. ISO confirmed it in 2023 with no revision under way.
What auditors look for: Traceable standards, validated or verified methods, monitoring of result validity, an evaluation of measurement uncertainty, and records complete enough to repeat the work.
The reality of accreditation
One lab. Several auditors.
Most environmental labs do not answer to a single program. A lab can hold drinking water certification at home, NELAP accreditation for wastewater and soil, secondary accreditation in every state its clients ship from, and DoD ELAP for federal work. Each brings its own auditor, its own checklist and its own questions about the same initial calibrations.
State certification program
Drinking water certification or a state lab program audits the methods you run for that state.
NELAP accreditation body
Your primary NELAP body audits you against the TNI standard across your fields of accreditation.
Secondary and reciprocal accreditation
States your clients sample in may grant reciprocity, review your records, or require their own certification and audit.
DoD ELAP and data validators
QSM audits, third-party data validation and client audits all ask how each calibration was evaluated.
One calibration record that holds up in front of every auditor. WLTR evaluates each initial calibration the same way every time, against 19 acceptance criteria, and keeps the documented record. Whichever auditor walks in, the evidence is the same. Accredited in more than one state? Bring an ICAL from each to the pilot program.
Standards updates
What changed, and what it means for calibration.
-
June 30, 2026
DoD ELAP deadline for QSM 6.0 accreditation
All DoD ELAP laboratories had to hold QSM 6.0 accreditation by this date or lose accreditation status.
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May 23, 2026
TNI releases voting draft of a quality management module aligned to ISO/IEC 17025:2017
A voting draft of Volume 1 Module 2 rebuilds the general lab requirements on ISO/IEC 17025:2017 text.
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May 20, 2026
EPA formally proposes PFOA/PFOS compliance extension and rescission of four PFAS limits
Proposed rules would extend PFOA and PFOS compliance to 2031 for some systems and remove four other PFAS limits.
-
April 9, 2026
DoD EDQW issues QSM 6.0 supplemental information, version 9
New supplemental information to read alongside the QSM 6.0 calibration and QC tables.
Questions
Frequently asked questions
What is the difference between TNI and NELAP?
TNI, The NELAC Institute, writes the environmental laboratory accreditation standard. NELAP is the program in which 14 state agencies accredit labs to that standard and recognize each other’s accreditations.
Does my state require TNI accreditation?
It depends on the state and the type of data. NELAP states accredit to the TNI standard directly, other states run their own programs, and many certify only drinking water labs. Use the state finder above, then confirm the current rules with the agency.
What is secondary accreditation?
A lab accredited by one NELAP accreditation body can apply to another NELAP body for secondary accreditation based on its primary accreditation, instead of going through a full new assessment.
Why do auditors care how an initial calibration was chosen?
Every reported result depends on the ICAL. Standards and guidance increasingly expect labs to judge a calibration by relative error at the low and mid levels, because a high correlation coefficient can hide large errors near the reporting limit.
How often is this page updated?
We review the standards and the state list regularly and post changes in Standards Updates. Each entry links to its primary source so you can confirm it.
Can I comment or suggest a correction?
Yes. Every Standards Update has a comment section. Comments are reviewed before they appear. If a state entry is out of date, leave a comment on the latest update or contact admin@wltr.tech.
Before your next assessment
See how your initial calibrations hold up.
Bring a recent ICAL. We will show you how each analyte’s calibration holds up against 19 acceptance criteria, with the evidence an auditor will ask for.
This page is a plain-language summary for orientation, not legal or regulatory advice. Sources: The NELAC Institute (TNI) · EPA drinking water laboratory certification · EPA SW-846 · DoD EDQW.