Assessing a New Bacteria Monitoring Technology by Using the US-EPA ATP Protocol to Compare with Reference Methods

Collaborative Efforts to Improve Environmental Monitoring
Oral Presentation

Prepared by R. Brown1, E. Marcotte2, D. Wilton2, C. Fricker3, L. O'Donnell1
1 - Queen's University, Dept. of Chemistry and School of Environmental Studies, 90 Bader Lane, Kingston, ON, K7L3N6, Canada
2 - TECTA-PDS Inc., 382 King St. West, Kingston, Ontario, K7K2Y2, Canada
3 - CFR Consulting, 118B Oxford Rd., Reading, Berkshire, RG17NG, United Kingdom


Contact Information: stephen.brown@chem.queensu.ca; 613-533-2655


ABSTRACT

The US-EPA ATP protocol for wastewater and ambient water was used to develop a laboratory study to validate the E. coli (EC) and Fecal Coliform (FC) testing technology from TECTA-PDS by comparing with reference methods (US-EPA Method 1603, mTEC for EC; APHA Method 9222D, mFC, for FC). Final sewage samples were spiked with secondary effluent (or diluted) to reach a target range suitable for the reference tests. Replicates were analyze by adding 100 mL samples to single-use test cartridges containing all required ingredients. The TECTA system provided rapid results with automated detection through continuous monitoring of the broth culture test cartridges in a dedicated incubator. It provided automatic detection with results transmitted by e-mail, while a technician interpreted the reference tests the end of a 24 h prescribed period. TECTA samples were confirmed using a multi-step procedure developed using the guidelines of the ATP protocol. Preliminary studies showed that the TECTA system provided quantitative results in agreement with the reference methods for both EC (84±47 vs 72±10 cfu/100 mL) and FC (50±20 vs 61±8 cfu/100 mL) parameters. The false positive rate (EC: 8.0%, FC: 0.0%) and false negative rate (EC: 0.0%, FC: 1.3%), determined for 120 samples, were within an acceptable range. The TECTA results were all provided in 8 to 11 hours, compared with 24 h for the reference methods.