The Minnesota Department of Agriculture (MDA) requires that a current Quality Assurance/Quality Control (QA/QC) plan from a proposed commercial laboratory as well as specific analytical methods be pre-approved by the MDA for most agricultural chemical investigations. A QA/QC plan and analytical methods which were approved by the MDA and/or updated within the last two years are generally acceptable for fulfilling this requirement. Refer to Section D of this document for information required to be submitted or reported to the MDA. Please be aware that all laboratory data submitted to the MDA are subject to the reporting requirements listed below in item D.8.
The MDA maintains standard analytical lists for pesticides commonly required for agricultural chemical investigations in Guidance Document 26 Analytical Lists for Pesticide Incident Investigations. The MDA does not require specific methods for these analyses, therefore the proposed analytical methods also must be pre-approved. The minimum acceptable reporting limit will vary from compound to compound. Specific reporting limits for MDA standard list compounds in soil and water are attached to this document. The MDA laboratory staff will be available to discuss proposed analytical methods.
B. Nutrients – Nitrate/Nitrite-Nitrogen, Total Kjeldahl Nitrogen, Ammonia/Ammonium-Nitrogen
Nitrogen analyses required on agricultural chemical investigations for the compounds listed in Attachment 1 must have MDA approval for water and soil matrices. The laboratory will follow the requirements listed in Part D. of this document. Specific reporting requirements for MDA Standard list compounds are included in Attachment 1.
As a service to the public, the MDA will maintain and distribute a list of commercial laboratories (GD23 Pre-approved Commercial Laboratories: Fixed Base and Mobile) with MDA pre-approved QA/QC plans and analytical methods for standard MDA list compounds. All information provided to the MDA will be public information unless clearly marked as a trade secret under Minn. Statutes, Section 13.37, Subd. 1(b).
C Additional Compounds
Additional compounds that could be requested on a site, including but not limited to arsenic, pentachlorophenol, polynuclear aromatic hydrocarbons (PAHs) and dioxins require the laboratory have ISO 17025:2005, National Environmental Laboratory Accreditation Program (NELAP), or Minnesota Department of Health Laboratory Accreditation. The laboratory will provide the current scope list and certificate for the accrediting authority to MDA.
With the exception of MDa List pesticides and nutrients described above, the accreditation must be for the same compounds of interest at the site. There may be some exceptions to this requirement that will be handled on a case by case basis. Again, the MDA does not require specific methods for these analyses; therefore proposed analytical methods for non-accredited compounds also must be pre-approved.
D. Commercial Laboratories
Commercial laboratories performing work for agricultural chemical investigations involving MDA pesticides and nutrient analyses must provide the information described below to the MDA prior to doing work on a site.
Please direct any general questions or correspondence to: Jim Seaberg, Laboratory Coordinator, Pesticide and Fertilizer Management Division at (651) 201-6139.
Reporting Limits (R.L.)
651-201-6061 • Fax: 651-201-6112
Pesticide & Fertilizer Management Division