Indiana Department of Health
Indiana environmental lab certification, a drinking water program.
Which Indiana agency certifies your lab, what the Department of Health reviews, how out-of-state labs qualify, and what auditors look for in your initial calibrations.
At a glance
How environmental lab certification works in Indiana.
Indiana is not a NELAP state. The Indiana Department of Health certifies laboratories that analyze drinking water, and IDEM’s wastewater compliance pages describe no laboratory certification program.
Drinking water lab certification
- Program
- Drinking Water Laboratory Certification, run by the Indiana Department of Health (IDOH) Laboratories
- Legal basis
- Indiana’s drinking water rules in 327 IAC 8, administered by the Indiana Department of Environmental Management (IDEM), count a compliance sample only if a laboratory certified by the commissioner or the U.S. EPA analyzed it (327 IAC 8-2-33), and other sections name labs certified by the Indiana Department of Health. Federal rule 40 CFR 141.28 sets the same condition.
- Who needs it
- Labs analyzing drinking water compliance samples. Under 40 CFR 141.28, measurements such as alkalinity, disinfectant residual, orthophosphate, pH, silica, temperature and turbidity may be performed by any person acceptable to the state.
- Disciplines
- Chemistry and microbiology certification, each with its own pre-audit form. IDOH also lists certified radiochemistry laboratories.
- Wastewater
- IDEM’s pages describe no laboratory certification program. IDEM offers laboratory technical assistance with NPDES approved test methods and runs DMRQA: major dischargers participate annually, minor dischargers on a three year rotation.
- Out-of-state labs
- IDOH recognizes certification granted by other states and TNI. Labs register, submit home state or TNI certification documents and their latest drinking water audit report, pay an annual reciprocal fee, and copy Indiana on WS-PT results.
- NELAP status
- Not a NELAP accreditation body, as of October 2026
The accreditation cycle
From application to certification.
The steps below summarize the Indiana Department of Health’s drinking water certification pages. Those pages do not state a certification period, so your certificate and IDOH correspondence govern the term and renewal.
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Pre-audit request
Chemistry labs file State Form 56453 and microbiology labs file State Form 56454, with the quality assurance plan or manual and SOPs for every method sought.
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Proficiency testing
Two successful WS-PTs per chemistry method and analyte. For microbiology, one for enzyme substrate methods and two for all other methods.
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Supporting data
Both disciplines submit staff qualifications and training records. Chemistry labs add a current MDL study for each method and analyte, and microbiology labs add QC results for the current lot of bottles, media and dilution water.
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On-site evaluation
After document review, an Indiana laboratory certification officer conducts an on-site evaluation of the lab.
Initial calibration
What auditors check in your initial calibrations.
Indiana’s certification pages set no calibration criteria of their own. The requirements come from the EPA drinking water methods a lab is certified for under 40 CFR 141, and IDOH reviews your quality assurance plan, SOPs and detection limit studies before it visits.
A range that brackets what you report
The lowest standard should sit at or below your reporting limit and the highest at or above the top concentration you report. Results outside the calibrated range need to be qualified.
Error at the low end, not r² alone
A correlation coefficient of 0.999 can still hide a low standard that back-calculates 30 percent off. Auditors look at relative error, especially at the lowest levels.
Records that rebuild the curve
Raw responses, the model and weighting used, any excluded points with the reason, and the verification that followed. An auditor should be able to reconstruct every initial calibration from the record.
Documents reviewed before the visit
IDOH asks chemistry labs for the quality assurance plan or manual, SOPs for every method sought, and a current MDL study for each method and analyte. Calibration criteria come from the EPA methods required under 40 CFR 141, so the SOPs the certification officer reads should carry them.
Source: Indiana Department of Health, Drinking Water Laboratory Certification; 40 CFR 141 subpart C method tables, e.g. 141.23(k)(1)
Out-of-state labs seeking reciprocity send IDOH their most recent home state or TNI drinking water audit report, so any calibration findings in that report are part of what Indiana reviews.
Self-check
Are your initial calibrations ready for an Indiana assessment?
Tick what your lab could show an auditor today. Nothing you select is saved or sent anywhere.
6Checks to work through
Select each item your lab could show an auditor today.
A self-assessment to help you prepare, not a compliance determination.
Indiana specifics
In Indiana, lab certification means drinking water.
The Indiana Department of Health certifies drinking water laboratories in chemistry and microbiology and lists certified radiochemistry laboratories. IDEM’s wastewater compliance pages describe no laboratory certification program. They instead offer laboratory technical assistance with NPDES approved test methods and describe the DMRQA program, in which major dischargers participate annually and minor dischargers on a three year rotation.
Out-of-state labs work through reciprocity. IDOH recognizes certification granted by other states and TNI, and asks for home state certification documents that list certified methods and analytes, the effective and expiration dates, and the certifying authority’s signature, along with the latest drinking water audit report. Indiana must then be copied on WS-PT results going forward.
Two recent changes are worth tracking as of October 2026. IDEM’s LSA Document #24-428, Drinking Water Reference Updates; Lead and Copper, went to the Environmental Rules Board for final adoption on October 16, 2025 and incorporates federal drinking water rules by reference at 327 IAC 8-2.7 and 8-2.8 once effective. IDEM’s January 2025 PFAS laboratory list notes that IDOH is not performing PFAS tests for public water systems and draws on labs certified by U.S. EPA for UCMR 5 and by Michigan EGLE for PFAS.
How WLTR helps
Calibration evidence ready for an Indiana certification audit.
WLTR independently reviews the calibration your instrument software produced. Your analyst still makes the final call. What changes is that the evidence is complete, consistent across analysts, and ready before the auditor asks for it.
- Each analyte reviewed one at a time in the instrument software.
- The model and weighting are whatever the batch was processed with.
- r² is the number most people look at, even though it does not measure error at the low end.
- QA signs off without an independent check on the curve.
- Every analyte and every candidate model side by side in the Calibration Intelligence dashboard.
- Diagnostics run automatically and the best fit curve is identified, with the reasons recorded.
- Relative error at every level, including the lowest standard, shown on one screen.
- A traceable record your QA manager can review, sign and hand to an Indiana laboratory certification officer.
See how your own ICAL data looks when every analyte and model is laid out for review.
Questions
Indiana accreditation FAQs
Is Indiana a NELAP state?
No. Neither the Indiana Department of Health nor IDEM is on TNI’s list of NELAP recognized accreditation bodies. For out-of-state labs, IDOH does recognize certification granted by other states and TNI.
Who certifies drinking water labs in Indiana?
The Indiana Department of Health, through its Drinking Water Laboratory Certification program. Under 327 IAC 8, compliance samples must be analyzed by a certified laboratory, and several sections name labs certified by IDOH or the U.S. EPA.
Does Indiana certify wastewater labs?
IDEM’s wastewater pages describe no laboratory certification program. IDEM offers laboratory technical assistance with NPDES approved test methods, and dischargers take part in DMRQA studies, majors annually and minors on a three year rotation.
Can an out-of-state lab analyze Indiana drinking water samples?
Yes, through reciprocity. The lab completes the Drinking Water Laboratory Registration, submits its home state or TNI certification documents and latest audit report, pays an annual reciprocal fee, and copies Indiana on its WS-PT results.
Does Indiana have its own initial calibration rule?
Not in the sources we reviewed. Calibration requirements come from the EPA drinking water methods required under 40 CFR 141, and IDOH reviews your quality assurance plan, SOPs and MDL studies before the on-site evaluation.
Sources
Primary sources for this page.
- Indiana Department of Health, Drinking Water Laboratory Certification (opens in a new tab)
- TNI, NELAP recognized accreditation bodies (opens in a new tab)
- IDEM, wastewater compliance evaluation (opens in a new tab)
- 40 CFR 141.28, certified laboratories (eCFR) (opens in a new tab)
- 40 CFR 141.23, inorganic chemical analytical methods (eCFR) (opens in a new tab)
- IDEM, PFAS laboratory list for community water systems (January 2025) (opens in a new tab)
- IDEM, LSA Document #24-428 information sheet (opens in a new tab)
This page summarizes public program information to help labs prepare. Requirements change, and the agency’s current rules and guidance always take precedence. WLTR is not affiliated with or endorsed by the Indiana Department of Health. Spot something out of date? Tell us at admin@wltr.tech.
Before your next assessment
See your Indiana ICALs the way a certification officer will.
Bring a recent initial calibration. We will walk you through every analyte and candidate model in the Calibration Intelligence dashboard, the best fit, and the record your QA manager would sign.
Request a demoHow the methodology works
Running environmental methods? See how WLTR works for environmental testing labs and water and wastewater utility labs.