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Riverbank Filtration Technology

A Green, Natural Alternative for Pre-treating
Surface Drinking Water

As energy costs for conventional treatment technologies escalate, translating into increases in user rates, alternative pretreatment technologies are being more widely used. Riverbank Filtration (RBF) technology is at the forefront as a method for not only pre-treating existing raw surface water supplies, but also for developing new and sustainable water supplies.

RFB is a natural pre-treatment process that uses the bed of reservoirs, lake or rivers and an adjacent sand and gravel aquifer as a natural filter. RBF can be applied directly to existing surface water reservoirs, streams, lakes, and rivers, and is often now a guiding factor in the hydrogeologic investigation of new source supplies.

Advantages of RBF

  • Natural pretreatment through bank filtration
  • Reduce chemical usage for pretreatment
  • Decrease construction and operation costs - lowest costs among supply options
  • Consistent water quality and temperatures - no spikes
  • Maintenance cost savings (no leaf debris which is common to surface water intakes)
  • Resistance to contaminant threats 
  • Minimal color, odor, turbidity, algae and other microorganisms
  • Reduction in disinfection by product precursors
  • Reduced need for disinfection
  • Ease of maintenance
  • Not susceptible to invasive plant infestation
  • Low profile and aesthetically pleasing - no scar to landscape or nearby recreational or environmental interests
  • No impact to fisheries 
  • Reduction in sludge generation
  • Achieves treatment removal credits (used to meet Long Term Enhanced Surface Water Treatment Rule)

Applications

Using alternative well technology, such as horizontal or angle wells, opens up numerous RFB applications depending on the site characteristics and soil conditions.

  • Fresh water intakes beneath river and lake beds
  • Saltwater intakes beneath ocean floor
  • Offset well head from wetlands, buildings and floodplains
  • High capacity single well pumping
  • Utilize aquifers beneath river and lakes to provide pre-filtration and enhance raw water quality (See related Manchester, NH case study in the side bar)
  • Tap aquifers from a distance where land constraints prevent drill rig access

Article Written By:

Gary L. Smith, P.G.
Senior Project Manager
Water Practice Group