Maine extension, state inspectors explain how farms can write food-safety plans and prepare for USDA GAP audits

Lindsay Warner, a produce-safety inspector who manages Maine’s contract with the U.S. Food and Drug Administration, and Bob Machado of the University of Maine Cooperative Extension led a virtual workshop on writing farm food-safety plans and preparing for third‑party GAP audits.

The workshop focused on why farms write food-safety plans, how those plans differ from compliance with the federal Produce Safety Rule (21 CFR 112), and how to prepare for USDA Agricultural Marketing Service (AMS) GAP audits, Warner said. “I really encourage people to go to the USDA AMS website to check for updates,” she said.

The distinction matters because the Produce Safety Rule is a federal regulation and inspection program; Warner said farms subject to that rule receive mandatory inspections every three to five years but are not required by that rule to have a written food-safety plan. Third‑party GAP audits, by contrast, are voluntary buyer-driven audits run under USDA AMS standards and generally require a written food-safety plan, far more records, and an auditor’s on-site review of biological, chemical and physical hazards.

Workshop presenters walked through the practical building blocks of a plan and the records auditors typically expect. Warner and Machado recommended keeping plans concise so farms do what they say: auditors will evaluate a farm against the plan’s written procedures. Warner put it plainly: “If it isn’t documented, it didn’t happen.” The presenters urged farms to focus on three high-priority sections when drafting a plan: employee training, a previous land‑use (soils) assessment, and an irrigation-water assessment.

On employee training, the presenters said auditors will interview workers; farms should document training dates, topics and attendees. Machado and Warner showed examples of common worker‑training and training‑attendance logs used to satisfy audit questions, and recommended tailoring templates to the farm’s operations rather than using overly large or generic forms.

Water testing and irrigation-risk guidance drew extended discussion. Warner explained that GAP audits require farms to know their irrigation water sources and to test them; she referenced the conventional benchmark used in assessments, the recreational‑water guideline of 126 generic E. coli per 100 milliliters. She described microbial “die‑off” as a reduction that can occur between water application and harvest, and gave the workshop’s rule‑of‑thumb math: a half‑log reduction per day (about a 68 percent daily reduction). Using that guideline, Warner walked through examples showing how higher raw counts may be acceptable if there are multiple days between the last irrigation and harvest, but cautioned that die‑off figures are a guideline, not a guarantee.

Warner also cautioned farms to choose the correct audit type for their buyers. GAP audit standards are modular: Parts 1 and 2 cover the farm, field harvest and field packing (the portions most buyers require); Parts 3 and 4 cover packinghouse, storage and transportation. She stressed farms should request the specific USDA AMS audit checklist their buyer requires to avoid paying for unnecessary scope.

Other practical points covered in the workshop: - Pesticide applicator licensing: Warner noted Maine requires a pesticide applicator license if a farm applies EPA‑registered pesticides on produce and sells more than the threshold cited in state guidance (she referenced the $1,000 sales threshold that applies for certain licensing requirements). - Record lists and templates: presenters reviewed a concise set of templates to attach to a plan (farm maps, harvest logs, cleaning and sanitizing records, preharvest assessments, mock‑recall/traceability logs, and soil‑amendment treatment records). Machado and Warner recommended keeping cleaning schedules targeted to food‑contact surfaces and grouping similar equipment by cleaning method and frequency. - Practical audits tips: do a self‑check a few days before an audit, make sure field and facility signs are posted, and keep a short plan so staff can consistently follow it during an on‑site audit.

Workshop participants asked about specific scenarios—animal droppings in fields, when to re‑sample after rain events, and whether produce testing is required. Warner and Machado said the GAP standards expect farms to document observations and corrective actions but do not prescribe an exhaustive “if‑this‑then‑that” list; rather, inspectors look for evidence that the farm assessed the hazard and took reasonable steps. On produce testing, the presenters said produce testing is rarely required in the farm setting and is more common in larger manufactured‑food systems or in buyer‑specific contracts.

The session closed with contact and resource guidance: the presenters pointed attendees to USDA AMS audit checklists, the Produce Safety Alliance and Cornell CALS GAPs materials, and offered follow‑up assistance. Organizers also reminded attendees of a follow‑up class on agricultural water assessment scheduled for Monday, April 28.