In a study conducted by Pall Life Sciences, data was collected on the Envirochek capsule using water ranging from 5-100 NTUs to demonstrate the predetermined amounts of clay dust in the water. 140 liters was chosen as an endpoint for gathering the data. The draft of U.S. EPA method 1622, which lists the Envirochek capsule as an approved technique, will only require 10 liters of water to be sampled. As Table 4 illustrates, it takes 11 minutes or less to filter 10 liters of water, with water ranging in turbidities from 5-100 NTUs. Limited testing also has shown that 10 liters of water at 1000 NTUs will pass through the Envirochek capsule in approximately 30 minutes.
All charts are an indication of typical performance.
Turbidity was controlled using clay dust. In this study, the Envirochek capsule demonstrated higher recoveries in various matrix conditions, the ability to filter 10 liters of water in highly turbid conditions, and the best overall performance when compared to one type of string wound cartridge that is required for Cryptosporidium testing under the current methodology. The time that is required for sample processing was significantly reduced, and a much lower eluate volume was produced. This reduced the time required for further processing steps, and increased recovery accuracy. Work is also occurring around the world to determine the safety of public drinking and recreational water.