Hard water in Morro Bay, CA
Reported by Morro Bay PW Dept - Water Division · November 2024
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Morro Bay water measures 149 mg/L (8.7 gpg) of hardness, hard by USGS standards. The number comes from Morro Bay PW Dept - Water Division, dated November 2024. Reports for this system disagree, with values from 149 to 489 mg/L.
At 149 mg/L, Morro Bay is 28 mg/L above the typical California figure of 121. Of the 10 nearest cities we track, 3 have softer water and 6 have harder. The range nearby runs from 39 mg/L in Atascadero to 604 in Nipomo.
What 149 mg/L means at home
Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.
Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.
Soap and detergent need a little more to lather, and soap scum shows up in the tub.
Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.
What to do about it
At 149 mg/L most of the trouble is scale, and only a few things deal with it.
Ion-exchange water softener
The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.
Salt-free conditioner
No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.
Reverse osmosis or carbon filter
Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.
3 people × 75 gallons a day × 8.7 gpg = 1,960 grains a day. A 24,000-grain unit regenerates about every 12 days.
EPA record for Morro Bay's water system
No health-based violations since 2016
Serves about 10,757 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.
Questions
Is Morro Bay water hard?
Yes. It measures about 149 mg/L (8.7 grains per gallon), which the USGS classes as hard.
What is the water hardness in Morro Bay in grains per gallon?
About 8.7 gpg. One grain per gallon equals 17.1 mg/L, so 149 mg/L divided by 17.1 gives 8.7.
What size water softener do I need in Morro Bay?
For 3 people using 75 gallons each per day, 8.7 gpg works out to about 1,960 grains a day. A 24,000-grain softener covers that with a regeneration about every 12 days.
Has the Morro Bay water system had EPA violations?
EPA records show no health-based violations for Morro Bay PW Dept - Water Division since 2016.
Nearby cities
- Atascadero39 mg/LSoft
- San Luis Obispo216 mg/LVery hard
- Pismo Beach149 mg/LHard
- Nipomo604 mg/LVery hard
- Santa Maria217 mg/LVery hard
- Orcutt233 mg/LVery hard
- Coalinga118 mg/LModerately hard
- Greenfield227 mg/LVery hard
- Soledad227 mg/LVery hard
- Lemoore Station100 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, November 18, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.