Moving to San Jose, CA? What to Know About the Water
Water quality essentials for anyone relocating to San Jose.
Water Hardness: 183 PPM (very hard)
If you are moving from a city with soft water, you will notice the difference immediately. San Jose's water at 183 PPM is classified as very hard. Expect mineral buildup on faucets and shower heads within weeks, spotty dishes, dry skin and hair, and significantly higher soap usage. Most San Jose homeowners with hard water install a water softener within the first year - it is the single most impactful water treatment investment for this area.
Contaminants to Know About
PFAS: San Jose has PFAS at 8.92 ppt, above the EPA limit of 4 ppt. These "forever chemicals" do not break down in your body. If you are pregnant, have young children, or plan to live here long-term, a reverse osmosis system or NSF P473-certified filter for your kitchen tap is a worthwhile investment ($200-$500). Learn about PFAS.
Lead levels are within normal ranges. If your new home has pre-1986 plumbing, a quick test ($15-$30) confirms your tap specifically.
Chlorine is present at 1.7 mg/L. This is above the taste threshold - you will likely notice a pool-like taste and smell, especially in showers. A carbon filter or shower filter ($30-$40) resolves this. San Jose Water is your water provider.
First-Week Water Checklist
Flush the pipes: Run every faucet (hot and cold) for 5 minutes after moving in. Water has been sitting in the pipes during the vacancy, and lead/copper levels are highest in stagnant water.
Check the water heater: Note its age (labeled on the unit). Set temperature to 120°F. In San Jose's hard water, tank water heaters last 8-10 years instead of 12-15. Tankless heaters are more vulnerable - check your manufacturer's warranty conditions for hardness limits.
Inspect fixtures: Look for existing scale buildup on faucets and shower heads. Heavy white deposits indicate the previous owners did not have a softener - and your plumbing may already have internal scale.
Request the CCR: Contact San Jose Water for the latest Consumer Confidence Report, which provides neighborhood-level water quality data.
Test your tap: A $15-$25 home test kit confirms whether your specific tap matches city averages. Worth doing if the home has older plumbing.
What to Budget for Water Treatment
Priority 1: Water softener. $600-$1,500 installed. This protects your plumbing, appliances, and quality of life from day one. Reduces scale damage on water heaters, cuts soap and detergent use, and extends appliance life. Full cost breakdown for San Jose.
Priority 2: PFAS filter. Under-sink reverse osmosis ($200-$500) for drinking and cooking water. Non-negotiable if you have kids or plan to start a family.
Nice to have: Shower filter. $30-$40. Noticeable improvement in skin and hair dryness within the first week. Easy to install, easy to justify.
Not sure where to start? Take the quiz - it factors in your budget, household size, and whether you rent or own.