The MDA requires that a current Quality Assurance/Quality Control (QA/QC) plan from a proposed commercial laboratory be pre-approved by the MDA for most pesticide incident investigations. A QA/QC plan on file at the MDA which was approved or updated within the last two years is generally acceptable for fulfilling this requirement. An outline of what should be included in a QA/QC plan is included below.

Methods for an individual pesticide or list of pesticides (GD 26 Analytical Lists for Pesticide Incident Investigations) has standard analytical lists for pesticide incident investigations are not currently specified by the MDA. Accordingly, 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. The MDA laboratory staff will be available to discuss proposed methods.

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).

For pesticide investigations involving only non-MDA list compounds (ex. wood treatment sites), commercial laboratories using standard EPA methods do not need to submit the information outlined below. However, the laboratory must hold current Minnesota Department of Health (MDH) state certification or current state certification from another state that has direct reciprocity with Minnesota. The certification must be for the same class of compounds of interest at the site. There may be some exceptions to this requirement that will be handled on a case by case basis. Also, please be aware that all laboratory data submitted to the MDA are subject to the reporting requirements listed below in section L. of the outline.

Commercial laboratories performing work for pesticide investigations involving MDA list compounds must provide the information outlined below to the department prior to doing work on a site.

Analytical Methods: The laboratory will provide the written methodologies employed by the lab. Since the analytical methods used in this program are performanced based, the laboratory needs to provide supporting documentation that validates the method meets program criteria.

The minimum reporting limits that must be met for the compounds of interest are attached to this document.

For initial demonstration of the analytical method to be used by the lab, a method detection level study is required with each method and matrix. 40CFR Part 136, Appendix B protocols will be followed and a minimum of seven replicates, 1 to 10 times the estimated MDL, will be submitted. The recoveries of the seven replicates should fall within 70 - 130%. If the laboratory has difficulty achieving these limits, contact the Department for assistance. An additional document that provides guidance for MDLs is the Wisconsin Department of Natural Resources "Analytical Detection Limit Guidance & Laboratory Guide for Determining Method Detection Limits", April, 1996.

Once a laboratory is in the program, the laboratory must provide yearly precision and accuracy data analyzed at the required reporting level. The laboratory can provide this in the form of a method detection limit study or run 9 to 20 matrix spikes and matrix spike duplicates at the reporting limit. The precision data for each compound should be less than 20 relative percent difference (RPD). The accuracy data should fall within 70 - 130%. The precision and accuracy studies should be submitted to the Department by March 1 of the upcoming sampling season. Laboratories that fail to provide this information or do not meet the criteria listed by this date will be removed from the approved laboratory list.

The laboratory will participate in a proficiency testing (PT) program. Please refer to the A2LA website for approved providers. PT samples will be submitted to the Department yearly. Compounds that fall outside the performance limits will require corrective action. Corrective actions will be forwarded to the Department.

1. A QA manual and supporting documentation (e.g. SOPs) will be submitted: The following information needs to be included:
1. Personnel:
• Credentials
• Designated Sample Custodian
• Quality Assurance Officer
• Primary Laboratory Contact
2. Description of building and storage security
3. Lab sample storage and handling procedures including:
• Sample receiving
• Sample acceptance
• Chain-of-custody
• Turnaround time from receipt of samples to sample analysis and reporting of data
• Sample disposition after analysis
4. Maximum holding times and preservation for samples according to approved methodologies(e.g. refrigeration, freezing)
5. Sample preparation
6. Complete itemization of lab equipment including:
• Specific name and model
• Maintenance schedule
• Calibration procedures in terms of accuracy, precision and references, and frequency of calibrations
• Preventative maintenance
7. Preparation of reagents and reagent grade water
8. Source of analytical standards
9. Quality control:
• Blanks
• Replicates
• Duplicates
• Spikes
• Number and frequency
• Inter-laboratory quality control
• Instrument test mix
• Check sample program(s)
• State Certifications
• Audits
• Corrective actions
10. Method detection limit procedure
11. Routine assessment of data precision, representation, comparability, accuracy, and completeness of specific measurement of parameters involved:
• Personnel responsible
• Methods for validation
12. Reporting requirements: (provide an example report)
• Submittal date
• Date of extraction
• Date of analysis
• Results of required analysis
• Method detection and reporting limits
• Results of field quality control samples
• Related quality control recoveries(spike recoveries, duplicate expressed as RPD or RSD)
• Surrogate Recoveries as appropriate
• Assessment of data
• Discussion section if necessary to describe any problems encountered
• Other information required by order, permit, etc.
13. Client Complaints/Corrective Action
2. Provide names, phone numbers and E-Mail address of primary contacts in the laboratory.

Please direct any general questions or correspondence to: Paul McNelly , Laboratory Coordinator, Pesticide and Fertilizer Management Division at 651-201-6560 or Louise Ogden, QA Officer, Laboratory Services Division at 651-201-6682. Questions on analytical methods should be directed to: Kathy Reynolds, MDA Water Chemist at 651-201-6354 and Ed Balcer, MDA Soil Chemist at 651-201-6532.

MDA Contact

651-201-6061 • Fax: 651-201-6112
Pesticide & Fertilizer Management Division