Q: How does biofouling and its control affect water treatment?
A: Bacteria, oxidized iron and manganese, sulfur, and other slimy products are slow killers of resin beds and many iron/manganese removal and filtration devices. Biofilms overwhelm and defeat carbon filters–even "bacteriostatic" types and bactericidal resins. They also attack or plug reverse osmosis membranes and cartridge filters.
Aeration-type or redox-media, backwashable iron filters tolerate biofouling pretty well and make good screening filters for most water systems, small or large. They have to be designed and maintained well, taking the biofouling into consideration including making sure the backwash is effective in removing most of the accumulated iron debris in the filter bed periodically.
Q: When is the best time to clean up a biofouling problem such as iron bacteria?
A: The best time, obviously, is as early as possible, before real damage occurs and treatment methods are most effective. This is usually long before noticeable plugging, loss of efficiency, and other gross symptoms become noticeable. The key to catching a growth before it causes a problem is preventive monitoring-starting when the well is new. This advice also applies to private water and monitoring wells.