Preparing for Audits: What Water Laboratories Should Know

If your water laboratory is seeking Environmental Protection Agency (EPA) or state certification for analyzing drinking water samples, your laboratory will need to undergo periodic audits. This includes passing an on-site audit minimally once every three years, plus conducting proficiency testing annually for analytes processed by your laboratory.

There may be other reasons your laboratory undergoes an audit, such as if you're seeking certification to ISO 17025 for testing and calibration laboratories. Whatever the reason, here's what you should consider when preparing for an audit.

Get Your Documentation In Order

A key preliminary step in preparing for a laboratory audit is to pull together documents that auditors will typically review prior to or at the start of the audit. Your laboratory's quality assurance (QA) plan is an important place to start. For EPA certification, this should include:

  • Laboratory personnel roles, responsibilities, qualifications, and training records
  • Process for identifying clients' data quality objectives
  • Standard operating procedures (SOPs) covering all laboratory activities (which should be signed, dated, and reviewed annually)
  • Field sampling protocols
  • Sample receipt and handling procedures, including chain-of-custody protocols
  • Instrument calibration methods
  • Preventive maintenance procedures
  • Analytical methods and quality control (QC) procedures
  • Data handling processes, including reduction, validation, verification, and procedures for corrections
  • Types of QC checks and their frequency
  • Schedules for data quality audits
  • Corrective action processes
  • Recordkeeping procedures

Carefully review any documentation requirements provided in the ISO standard or by your accreditation body. For more detail on what to include in your QA plan for EPA certification, see the EPA Laboratory Certification Manual for Drinking Water.

Review Laboratory Notebooks

Data integrity issues are a common problem in the industry. Auditors may examine your laboratory notebooks, so you'll want to make sure of the following:

  • All data should be recorded in notebooks; nothing should be recorded on scrap paper to later be transcribed.
  • Notebooks should be bound with numbered pages that can't be removed.
  • Loose pages, such as instrument-generated printouts with appropriate descriptions, should be attached to the notebooks with tape.
  • Data points and records should not be erased or whited out, but indicated with strikethrough where needed.

Do a Lab Walkthrough

It's worth conducting a walkthrough ahead of your audit to make sure there aren't any obvious issues that will attract scrutiny. Specifically, pay attention to the following during your walkthrough:

  • Labeling and reagents: Make sure all materials on the bench top are clearly labeled. Check that reagents used in any assays have not expired.
  • Chemical storage: Flammables, acids, and bases should all be stored separately and in appropriate OSHA-approved storage cabinets.
  • Trip hazards: Slip, trip, and fall incidents are the most common injuries in the workplace. Watch for extension cords, wet areas, and debris or boxes.
  • Emergency procedures: Your emergency plan should be visible along with contact numbers in case of a spill. Exits should be accessible and not blocked in any way (for example, by a pile of empty shipping boxes).
  • Housekeeping: Instruments should be free of clutter and visible residues. It goes without saying that there should be no open food or drinks in the lab.
  • Worker attire: Employees should wear close-toed shoes, and long hair should be tied back. Verify the appropriate use of personal protective equipment.
  • Hood use: Verify that laboratory technicians are using hoods appropriately and that hoods aren't being used as chemical storage.

Conduct an Internal Audit

Conducting an internal audit can help proactively identify gaps ahead of an official audit. Effective preparation goes a long way toward avoiding audit findings that your laboratory has to correct in order to maintain certification.

ISO 17025 requires laboratories to perform internal audits at planned intervals, while the Association of Public Health Laboratories recommends laboratories audit each part of the management system annually. Best practice is to give plenty of time—at least three months—between your internal audit and an official laboratory audit.

Prepare Your Team

When auditors visit, you can expect they will ask your laboratory personnel questions. Although an effective laboratory training program can set your team up for success at the start, it's worth it to carve out time ahead of the audit specifically to prepare your team. Items to review include:

  • The laboratory QA plan
  • Any SOPs relevant to their role
  • Procedures for ensuring data integrity, including notebook procedures
  • Safety procedures
  • Whether laboratory managers or others need to be included in conversations with auditors

With careful forethought, laboratory audits don't need to be a stressful experience. Taking the time to thoroughly address documentation requirements, data integrity, and safety procedures will pay dividends—not just during the audit but also in your laboratory's reliability.

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Rachel Tracy
Professional Writer

Rachel Tracy is a technology and science copywriter with a background in environmental and water science. She holds a master’s degree in environmental science from Vanderbilt University and has experience working in a variety of laboratory settings, including water testing and biomedical labs. Rachel is a former environmental consultant with expertise in regulatory compliance, global management standards, and quality and safety management. She lives in Nashville, Tennessee.