Manual Sample Collection

     Data were derived from manual collection of samples along the filter strip during overflow events.  We monitored dissolved oxygen (DO) in water at the time of collection and noted the pattern presented in Figure 1.

Microbiological Analysis of Samples

      Composite soil samples were taken along a transect at right angles to the water flow down the filter strip at 1 m from the discharge pipe and at 5 m, 10 m, 20 m, 40 m, 80m and 150 m from the outfall.  The composite soil samples were homogenized in Whirlpaks and transported to the laboratory on ice in a cooler.  Samples were diluted to 10-4, 10-5, and 10-6 and plated on agar with selective nutrients. Microbial colonies were counted after 3 to 7 days of growth.  A pattern of pupulation change was noted in various species along the filter strip as presented in Figure 2.

 

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