To Protect Populations - Drip Filters

About First Water

Water Treatment

First Water Products

First Water drip filters can be fitted with filter elements from different sources according to customer requirements. Filter elements are graded by First Water according to their efficacy and durability.

The efficacy of a filter is indicated by its Log Reduction Value (LRV). The LRV indicates the order of magnitude by which contaminants in the untreated water are reduced. For example, if a filter challenged with untreated water containing 1 million faecal coliforms (FC) per 100ml reduces the contamination to 1 FC/100ml then the LRV=6, equivalent to a 99.9999% reduction.

Grade A filter elements are manufactured to the highest standards and will provide bacterial log reduction values in excess of 6.Grade A filters are impregnated with silver for additional bacteriostasis. KATADYN filter elements are rated Grade A+ because each filter is pressure tested. The core of KATADYN filter elements can be filled with activated carbon or with silver-coated gravel or can be left empty to reduce weight.

Grade B filter elements provide LRV's in the range 4-5. These filter elements are impregnated and/or coated internally with silver.

Grade C filter elements do not contain silver and provide LRV's in the range 2-3.

Other components of the drip filter including the tap and plastic container can be varied according to customer specification.

For advice or further information including pricing, please email enquiries@firstwater.info or contact one of our regional offices.
All First Water products are designed for distribution to populations during emergencies and to meet longer-term development objectives. We aim to offer the highest quality products at the lowest possible prices.

Grade	LRV (bacteria)	Bacteriostasis	Quality Control	Capacity (litres)	Cost per candle (U.S. dollars)	Cost per 1,000 litres of water (U.S. dollars)
A	>6	Silver impregnated	Total	50,000	9-10	0.20
B	4-5	Silver coated	Some	12,500	2-3	0.24
C	2-3	None	None	5,000	1	0.20