Region 8
Whole Effluent Toxicity (WET) Testing Laboratories
While no formal national USEPA certification program is in place for aquatic biology laboratories performing toxicity tests as part of the NPDES program, Region 8 has suggested items to look for from a WET testing laboratory:
- Analytical data that is accurate and defensible
- Complete data packages
- Up-to-date standard operating procedures (SOPs)
- Ability to maintain a qualified staff
- Quality control and reference toxicant control charts supplied with all analysis
- Discharge Monitoring Report-Quality Assurance (DMRQA) information
- Turn-around times and temperatures are met
- Complete Chain-of-Custody (COC) forms
- NELAC certification/Audit Reports
- Additional certifications
- Clean facility with knowledgeable staff
Lab Audits
You should ask the lab if they've had an on-site evaluation from an accrediting authority, such as NELAP. If there has been an on-site evaluation, you may want to see a copy of the audit report and the lab's response to any deficiencies cited in the report.
Lab visit
If visiting the lab, it may be wise to view the organisms used in testing. The organisms should appear active and healthy. If fish appear sluggish, this may be an indication of health problems. C. dubia should be free swimming, not floating or immobile. Aquariums, culturing chambers, and culturing areas should be clean and organized. Culture areas should be separate from testing areas so that cross-contamination can't occur.
Culture Records
The lab should be able to provide records documenting where their organisms came from originally. Species confirmation must be performed annually and the lab should have records on file documenting that they use the correct species. If organisms from an outside supplier are used, ask who the supplier is and have the lab provide the documentation from the supplier regarding the health of the organisms. If the lab performed a reference toxicant test when the organisms first arrived in the lab, ask for a copy of those results.
Reference Toxicant Testing
Another way to compare laboratories is to look at the reference toxicant tests that have been generated. The Methods Manual requires that each lab demonstrate its ability to obtain consistent, precise results with reference toxicants before it performs tests with effluents for permit compliance purposes.
Laboratories with very wide control limits, and/or many points outside of the control limits, should be investigating problems related to the quality of the data being produced. A series of exceedances of either the upper or lower control limit after establishment of the control chart should prompt a review of the culture and test systems, as they may cause effluent tests completed during the month(s) of the exceedances to be questioned.
Lab staff
Permittees should ask to see the training files of lab staff and insure that each lab technician has the necessary combination of experience and education to adequately demonstrate a specific knowledge of their particular function and a general knowledge of lab operations, analytical test methods, QA/QC procedures, and records management. Lab management should be able to certify that personnel with appropriate educational and/or technical background perform all tests for which the lab is accredited.
Lab Selection Based on Quality, Not Cost
Because lab selection can be such an important factor in test results, it is important that the experience of the analysts be carefully considered. The educational qualifications and experience of the lab individuals who will actually perform the tests, as well as the qualifications of the supervisory staff, should be reviewed prior to lab selection. The toxicity testing lab should demonstrate a serious commitment to a QA/QC program that extends beyond analyst experience. Considerations such as an ongoing reference toxicant program, a two-tiered review process for all toxicity test data and summary reports, a good sample custody tracking system that is always used, proper equipment maintenance, dilution water quality monitoring, facility maintenance, and attention to test organism health are all characteristics of a lab that is committed to generating quality data.
The costs associated with more experienced and better qualified laboratories can be higher than those of the less qualified laboratories, and many entities are constrained by existing procurement regulations that require the selection of the least expensive (and potentially least qualified) bidder. Perhaps one way to improve this situation is to convince the individuals responsible for making procurement decisions that WET testing is a professional service (much like engineering and chemical analyses services), which may give more latitude in selecting better qualified laboratories, rather than simply those that charge the least.
Probably the best lab-selecting tool is obtaining recommendations from others who have the expertise to critique lab performance. Since WET testing is required for many reasons, one can always find several individuals or firms who have been required to perform compliance toxicity tests, and it is very easy and straightforward to obtain information from them on how well (or poorly) their WET lab met their needs. The regulated community has every reason to be honest in their assessments, and as a consequence, this is probably the best source of information currently available for making a decision regarding selection of a WET lab.
If you would like a list of known laboratories that service facilities in Region 8, please contact:
Donna Roberts
303-312-6371
E-mail: roberts.donna@epa.gov
References: "Manual for the Evaluation of Laboratories Performing Aquatic Toxicity Tests" EPA-600-4-90-031 January 1991. Excerpts from "Selecting a WET Laboratory", Wisconsin Dept. of Environmental Quality"