OWML: QA/QC

Quality Assurance/Quality Control Manual: Ohio Water Microbiology Laboratory

Sample Management and Documentation
Samples for the bacterial indicators, E. coli, enterococci, fecal coliform, and total coliforms, are most commonly processed and analyzed in the field; however, they may be done in the Ohio Water Microbiology Laboratory (OWML). Holding times are 6 hours for compliance purposes and 24 hours for noncompliance purposes (American Public Health Association, 1998, Section 9060 B.) Adhering to a 6-hour holding time for all bacteriological samples, however, is highly recommended.

Samples for Clostridium perfringens and coliphage are processed and analyzed in the OWML; samples are kept on ice and processed within 48 hours of sample collection. Samples for the analysis of coliphage that arrive chilled within 48 to 96 hours from collection are acceptable, but the results are qualified. Samples for Cryptosporidium are processed in the OWML within 48 hours of sample collection. Samples for enteric viruses arrive at the OWML concentrated on filters; they must be kept on ice and processed within 24 hours of filtration. Samples for Actinomycetes are processed in the OWML; samples are kept on ice and processed within 24 hours of sample collection. Samples for bacterial markers generally arrive at the OWML as whole water samples; these samples are filtered and frozen within 24 hours of sample collection.

All requests for laboratory analyses must be submitted using a service request form (Appendix A). The following categories must be filled out when requesting sample analysis: station name, site number, date/time of sample collection, medium code, sample type, Water Center user code, and project number. The field personnel must check off requested analyses and make prior arrangements with laboratory personnel. Upon receipt of the sample in the laboratory, personnel will fill in Received By and Date Received on the front of the Service Request form.

Laboratory personnel will then enter sample information on to a log sheet (Appendix B) and log the sample into LIMS, which will assign a login ID. There is one sample logbook that contains a log sheet, service request forms, and results bench sheets. Laboratory personnel will write the login ID on the Service Request form (front and back) and on the sample bottle (or filter cartridge).

The Service Request form is filed in the sample logbook. Samples are stored in the laboratory refrigerators until processing. Appropriate bench sheets are routed to the analyst, who will enter sample login ID, processing date/times, and analytical information.

Upon completion of the analysis, the analyst writes final results on the back of the Service Request form. A second analyst routinely checks the calculations of the analyst performing the work. The results are entered into the LIMS. All data supported by NWIS will be sent to the Water Quality Data Transfer System (QWDX) and available for download at https://qwdx.cr.usgs.gov/. An email will be sent to all clients when the data is available for download. Other data will be sent directly to the client.

After all of the sample result information is distributed to the client, the Service Request form and appropriate bench sheets are then filed together in an archived folder sorted by login ID.