Please find the link to the following US EPA method:Method 1603: Escherichia coli (E.coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC) (September 2002)5 (PDF, 13 pp., 129 KB)

http://pdftohtml.spiritofanime.com/pdf2html.php?url=http://www.epa.gov/nerlcwww/1603sp02.pdf

Summary - This method (EPA 821-R-02-023) combines information from a 1985 publication (Test methods for Escherichia coli and Enterococci in Water by the Membrane Filter Procedure, EPA 600-4-85-076) and a subsequent March 2000 manual (Improved Enumeration Methods for the Recreational Water Quality Indicators: Enterococci and Escherichia coli, EPA/821/R-97/004). Method 1603 is a revised membrane filter (MF) procedure, a single-step method that uses one medium, modified mTEC Agar, and does not require the transfer of the membrane filter to another medium or other substrate.