Patent ID: 8167141

Claim:
A gravity-fed water filter, comprising: filter media including at least activated carbon and a lead scavenger; wherein the filter achieves a Filter Rate and Performance (FRAP) factor of about 350 or less according to the following formula: F ⁢ ⁢ R ⁢ ⁢ A ⁢ ⁢ P = [ V * f * c e ] [ L * 2 ] where: V=volume of the filter media (cm 3 ), f=average filtration unit time over lifetime L (min/liter), c e =effluent lead concentration at end of lifetime L when source water having a pH of 8.5 contains 90-120 ppb (μg/liter) soluble lead and 30-60 ppb (μg/liter) colloidal lead greater than 0.1 μm in diameter, and L=filter usage lifetime claimed by a manufacturer or seller of the filter (gallons).