Colony-forming units from SRA-WC/S and CON-WC/S biofilters were also evaluated for species-level identification of presumptive E. coli and thermotolerant coliform colonies. According to procedures described for the experimental setup, without the addition of E. coli stock solution to the influent water, two SRA-WC/S and two CON-WC/S biofilters that had not been tested in the synthetic stormwater protocol were flushed with synthetic stormwater for 30 min at a rate of 0.3 L/min (0.34 m/d). Samples were collected at 10, 20, and 30 min, diluted 1:10, 1:20, and 1:100 to clearly separate CFUs, and were plated using the Coliscan MF method.Two pink CFUs and seven blue CFUs from replicate biofilters were selected based on clear separation from other colonies and were subcultured from the Coliscan plate onto Brain Heart Infusion (BHI)agar. BHI plates were incubated for 24 h, inspected to ensure consistent growth without visible contamination, and were sent for phylogenetic analysis to the bacteriology identification laboratory Microcheck.