1. Research Microbiologist, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto ON, Canada M5S 1A4. E-mail: carole.baxter@utoronto.ca
2. Assistant Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto ON, Canada M5S 1A4. E-mail: hofmann@ecf.utoronto.ca
3. Ph.D. Candidate, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto ON, Canada M5S 1A4. E-mail: michael.templeton@utoronto.ca
4. Associate Professor, Dept. of Medical Genetics and Microbiology, Univ. of Toronto, 1 King’s College Circle, Toronto ON, Canada M5S 1A8. E-mail: martha.brown@utoronto.ca
5. Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto ON, Canada M5S 1A4. E-mail: andrews@ecf.utoronto.ca