More detail
Most of the cost is the equipment plus the plumbing labor to tie into your cold-water line, add a dedicated faucet, and connect a drain saddle. A cabinet with easy access is cheaper than one that requires drilling a granite countertop for the faucet.
Ongoing cost is modest: sediment and carbon pre-filters are replaced roughly annually and the RO membrane every two to three years. A unit certified to NSF/ANSI 58 is worth the small premium because it has been independently verified to reduce the contaminants it claims, including PFAS, lead, and arsenic.
Whole-house RO exists but is far more expensive and water-wasteful, so professionals almost always recommend point-of-use RO at the kitchen sink for drinking and cooking water, paired with a whole-house carbon system when broader protection is needed.
Related on this site
- Cost table: Reverse osmosis installation cost table
- Guide: Reverse Osmosis vs Whole-House Carbon for PFAS(6 min read)
- Service: Under-Sink Reverse Osmosis, Point-of-use RO certified to NSF/ANSI 58 — >99% removal of PFAS, lead, arsenic, and dissolved solids at the kitchen tap.