Many filter elements can show strong results that quickly decline. As such, we think it to be vitally important, with certain contaminants, that the reduction capability of our Black Berkey® elements be tested over time. Such tests provide the rate of decline in efficiency and allow our customers a verification that the rate of decline is not significant. As an example of a significant rate of decline, we are aware of other filter elements that claim fluoride reduction at 100%. Yet, in a time test and after only 40 gallons, the reduction rate falls to a mere 82.4%; this is nearly an 18% drop in performance after just 40 gallons. While an initial drop in efficiency is always expected, the 50 gallon test serves to verify that such drastic reduction does not take place with our Black Berkey® elements. For example, in our Gross Alpha reduction test, the efficiency reduces from 99.2% to 98.7% after 50 gallons. This represents a reduction in efficiency of only 0.5% (1/2 of 1%) after 50 gallons, which likely indicates that at the end of the 3,000 gallon life of the element, the reduction level should still be around 70%.
By the way, NMCL could have conducted the radiological contaminant reduction testing on the first gallon only, which would have been significantly less, in terms of cost. However, because of the serious nature of these particular contaminants, this would not provide our customers with a realistic understanding of how their elements would perform during a short term nuclear crisis situation. As such, the testing of the Black Berkey® purification elements was conducted to 50 gallons; an extreme situation and test. To our knowledge, this is the most gallons tested of any other purification element, which gives our customers a far better understanding of the element’s actual capabilities for removing radiological contamination from water in a highly contaminated hot zone.
Moreover, it is important to understand that radiological contamination is quite different from most other contaminants in that such contamination is typically not present in drinking water that is utilized over long periods of time. In most cases radiological contamination occurs after some sort of nuclear accident or event. In such cases the primary objective for those in the contaminated hot zone is to clear the area and to get to a non-contaminated zone as quickly as possible. It is highly unlikely that anyone would purposely remain in a hot zone for a long duration of time. Rather, during such events, the removal of radiological contaminants is typically needed for a short period of time during the evacuation process.
Additionally, it is important to keep in mind that most Berkey® systems come with at least two elements. Therefore, the reduction efficiency is effectively doubled with two elements. In systems with four elements, the reduction efficiency is quadrupled, six elements would mean six times the efficiency, etc.
For those who are unfortunate enough to be caught in a radiological contamination zone, it is recommended that the Black Berkey® purification elements be replaced as soon as is reasonably possible. This is because the more radiological contaminants the elements remove, the more radioactive the elements themselves become.
View Black Berkey® Elements Radiological Removal Test results: