These are installed when there are potential health risks associated with ingestion (drinking), dermal contact (washing hands) or inhalation (breathing the fumes coming from the water). Examples of these substances include pesticides, petroleum compounds, and solvents.
Performance data for carbon filters indicates that these filters perform extremely well for the removal of volatile organic compounds found in groundwater. The configuration of each installation is determined by the removal efficiency for that particular contaminant and the expected flow demand.
Because carbon is so effective at removing EDB, the most common filter system used for this contaminant consists of a five micron pre-filter, a flow meter, a single 54-inch tall by 10-inch diameter GAC tank, and an ultra-violet light for disinfection. This system has a capacity of 6 gallons per minute (gpm) and is sufficient for the average home. The filter media for all systems installed for EDB is exchanged (routine maintenance) annually.
GAC filters are very successful in removing solvents or petroleum products but filtering out Vinyl Chloride (VC) or Methyl-Tert-Butyl-Ether (MTBE) is more of a challenge. Filters on wells with VC are exchanged every six months and filters on wells with MTBE continue to be sampled quarterly and exchanged after a "break-through" at the mid-point.
POU filters are installed when the potential health risks are associated with ingesting (drinking) the water. Generally, in-organic substances such as Nitrate, Arsenic or Lead). RO filters are usually installed under the kitchen sink and are exchanged annually.
Where Nitrate standards are above the mcl at a Public Water System (PWS), a POE filter must be installed. For these systems, an Ion Exchange Filter, containing a nitrate removal resin, is installed which is similar in appearance to the carbon filters, although the process is quite different. The filter is regenerated with a brine solution to ensure the resin is performing satisfactorily.
The Florida Department of Environmental Protection is the state’s lead agency for environmental management and stewardship – protecting our air, water and land. The vision of the Florida Department of Environmental Protection is to create strong community partnerships, safeguard Florida’s natural resources and enhance its ecosystems.