According to the City of San Clemente Water Quality Report (2025 data), water from the City of San Clemente ranges from 14 to 17 grains per gallon of hardness by source, which the U.S. Geological Survey classes as very hard. Compare every city’s agency figure.
San Clemente runs its own city water utility, and its report prints hardness per source (14 gpg Metropolitan Water District water, 17 gpg Baker plant water) with no blend ratio, so the page shows a range. The report year is unusual: the city's groundwater plant was offline all year, so the supply was 100 percent imported. San Juan Capistrano next door is served by Santa Margarita Water District and Dana Point by South Coast Water District, not by their cities. No local restriction on salt-based equipment was found, which is absence of evidence.
A report year with no local water
The City of San Clemente prints hardness for each of its sources. Metropolitan Water District water is 14 gpg and water from the Baker treatment plant is 17 gpg, and the report gives no blend ratio. Both sit in the very hard band on the USGS scale, which is explained on the hard water by city page.
The report also says the city's groundwater plant was offline for the whole year. That makes the year unusual: it shows what an all-imported supply looks like, and it is not a guarantee of what the next report will say.
City water, and the neighbors who are not
San Clemente runs its own utility, so the city is your water provider if you are on its system. The neighbors are different. San Juan Capistrano is supplied by Santa Margarita Water District, not by its city, and prints a single average of 12. Dana Point is on South Coast Water District, which mixes imported water with treated local groundwater. Your bill names your supplier.
Chloramine in San Clemente
The city's report states that it disinfects with chloramine, which lasts longer in the pipes and is harder to remove than chlorine. Nuvia lists chloramine reduction for the Carbon CRS and the Advantage, and chlorine, taste and odor for the Sentry. Read whole-house water filtration for how carbon type matters before you compare systems.
Equipment rules in San Clemente
San Clemente's city materials show no restriction on residential salt-based water equipment. We have not read the sewer agency's rules line by line, so that is a lack of evidence and not a clearance. The statewide standards are explained on water softeners and conditioners.
A report year without the groundwater plant
San Clemente runs its own water utility, and in the report year its groundwater plant sat offline, so every gallon was imported: 14 gpg from Metropolitan Water District and 17 from the Baker plant, with no blend ratio printed. That makes it an unusual year to judge by, and a range is the fair way to show it. A later report with the plant running may read differently. A free in-home water analysis measures what comes out of your tap now, not what last year's report averaged. For drinking water at the sink, see reverse osmosis drinking water. The booking form follows.
Nearby cities
Sources
- City of San Clemente Water Quality Report (2025 data)
- Santa Margarita Water District Improvement District 9 Water Quality Report (2026 edition, 2025 water data)
- South Coast Water District Water Quality Report (2025 edition, 2024 water data)
- California Health and Safety Code, sections 116775 to 116795 (residential water softeners)
- USGS Water Science School: Hardness of water
Questions people ask
How hard is the water in San Clemente?
The city's report lists hardness by source instead of one average: 14 gpg for Metropolitan Water District water, or 236 mg/L, and 17 gpg for Baker plant water, or 293 mg/L. Both are above the 180 mg/L line USGS uses for very hard.
Why does San Clemente show a range and not one figure?
The city prints each source's hardness and no blend ratio, so nothing in the report says how much of each reaches your tap. A single number would be a guess.
Was San Clemente's water all imported?
In the report year, yes. The city's own report says its groundwater plant was not a source of supply that year, so the figures show an all-imported supply. A year with local groundwater could read differently.
Is the City of San Clemente my water provider?
For homes on the city's water system, yes. San Clemente runs its own utility. Neighboring San Juan Capistrano is different: its water comes from Santa Margarita Water District, not from the city.
Does San Clemente restrict salt-based water equipment?
Not that we found. We have not read the sewer agency's rules line by line, and those are the ones that count, so confirm your address before you buy.
Who is the best water filtration company in San Clemente?
Compare companies on six things you can check, not on who says they are best. (1) A free analysis of your own water before any quote. (2) Independent certifications: ask for the certificate and look it up with the certifier. (3) What the tanks, valves and media are made of, with flow ratings in writing. (4) A written warranty with a term for each part, because these systems are not cheap. (5) How long the company has been around: a warranty is only as good as the company behind it, and a warranty from a company that is gone is a worthless piece of paper and a big tank in your garage with nobody to call. (6) Reviews you can read. Nuvia Water offers a free in-home water analysis in San Clemente, was founded in 2012, holds California license 969902 (C-55 Water Conditioning), is BBB Accredited with an A rating, has a 4.6 Google rating from more than 1,600 reviews, and backs its Nuvia Pro dual-tank system with a 15-year media warranty and a 10-year control valve warranty. Nuvia's materials carry marks from IAPMO R&T, NSF, cUL us, UPC and ISO 9001 and 14001. Ask any company, including us, for the same papers.
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