ANSWER FIRST
Budget for the faucet and ongoing filters
The $650–$1,500 under-sink RO allowance is illustrative and depends on configuration. A written quote should identify membrane capacity, storage or tankless design, faucet, drain connection and installation labor. Refrigerator routing, a booster pump or leak protection may be separate items.
Compare annual cartridge costs, membrane replacement and sanitizing requirements. Rated production is measured under stated conditions; pressure and temperature at the property affect delivery. An under-sink system serves its dedicated outlets and does not soften showers or the water heater.
Three checks before the next step
- 01
Confirm all served outlets
- 02
Compare filters and membrane replacement costs
- 03
Check operating pressure and storage footprint
Compare the related treatment or service → · Try the educational decision check
Compare the connected outlets
A dedicated kitchen faucet, refrigerator line and tankless powered system can have different installation scopes. Ask whether faucet drilling, drain connection, tubing route, leak protection and commissioning are included. Compare the actual replacement-cartridge set and membrane cost.
Local evidence and its limits
The City 2026 report covers 2025 monitoring. SNWA regional guidance describes the broader water context; public-system results are not a measurement at your tap. Confirm your supplier and relevant property measurements. Sources reviewed 2026-10-18.
City report publication and monitoring period · SNWA home-treatment guidance