Fresno, CA water hardness
City of Fresno Department of Public Utilities publishes an average hardness of 89.3 mg/L (5.2 grains per gallon, also its own figure) for its system, in its City of Fresno Water Quality Annual Report 2024. On the USGS scale that is moderately hard water, though the utility's own range crosses more than one class — it spans moderately hard and very hard water from end to end.
The published figure, exactly as it appears
This is the hardness line transcribed from the source, with nothing added:
Total Hardness (as CaCO3) (mg/L, GPG) n/a 89.3 (5.2) 65-190 NO 2024
City of Fresno Department of Public Utilities, City of Fresno Water Quality Annual Report 2024
Units as published: mg/L, GPG. What kind of figure it is: an average with a range. Retrieved 2026-10-17.
Fresno hardness in mg/L and grains per gallon
Water-quality reports use mg/L (identical to ppm). Softener instructions and plumbing specifications use grains per gallon. Both are below. Where a figure is our arithmetic rather than the utility's own number, it says so.
| Figure | mg/L (ppm) | Grains per gallon | Whose number |
|---|---|---|---|
| Published average | 89.3 | 5.2 | both published by the utility |
| Low end of published range | 65 | 3.8 | mg/L published, gpg is our conversion |
| High end of published range | 190 | 11.1 | mg/L published, gpg is our conversion |
| Plotted on the scale above | 89.3 | 5.2 | published average; the gpg here is our conversion at 17.1, so it can differ slightly from a utility’s own rounded gpg figure |
The conversion, both ways: gpg = mg/L ÷ 17.1 and mg/L = gpg × 17.1. Worked for this system: 89.3 ÷ 17.1 = 5.2 gpg. The converter does °dH and °f as well, and why the factor is 17.1 explains where the number comes from.
What this figure does not tell you
Service area and source water
| Utility | City of Fresno Department of Public Utilities |
|---|---|
| Service area as published | The City of Fresno's water system. The report does not break hardness down by treatment plant or well field. |
Provenance of every number on this page
| Source document | City of Fresno Water Quality Annual Report 2024 |
|---|---|
| Source URL | https://www.fresno.gov/wp-content/uploads/2025/06/COF-Water-Quality-CCR-Report-ADA-062425_v5-10w783.pdf |
| Published by | City of Fresno Department of Public Utilities |
| Report year | 2024 |
| Year note | The hardness row is in Table 4, “Secondary Standards Contaminants Lists”, with a last-sampled year of 2024. |
| Retrieved | 2026-10-17 |
| Classification bands | USGS Water Science School, retrieved 2026-10-16 |
Notes the report forces on this page
- The report publishes the average in both units and the range in mg/L only. The grains figures for the range ends on this page are our conversion at 17.1 mg/L per grain.
- The published range crosses three USGS classes: 65 mg/L is moderately hard, the 89.3 mg/L average is moderately hard, and 190 mg/L is very hard.
- “n/a” is the report's secondary-MCL entry for this row and “NO” is its no-violation entry. Neither is a hardness value.
If you are sizing a softener for Fresno water
At 5.2 gpg, the sizing arithmetic starts from your household's water use, not from the hardness alone. The calculator below is pre-filled with this system's figure and every other input is an editable assumption.
Whether a softener is worth installing at this hardness is a judgement, not arithmetic, and it is not one this site makes for you. Nothing here has been tested by the author.
Where Fresno sits against other verified systems
- Portland, OR 9 mg/L 0.5 gpg Soft
- Boston, MA 16 mg/L 1 gpg Soft
- Manchester, NH 17.9 mg/L 1 gpg Soft
- Raleigh, NC 25 mg/L 1.47 gpg Soft
- New York, NY 32 mg/L 2 gpg Soft
- Charlotte, NC 32 mg/L 1.9 gpg Soft
- Memphis, TN 46 mg/L 2.7 gpg Soft
- Anchorage, AK 56 mg/L 3.3 gpg Soft
- Oakland, CA 68.4 mg/L 4 gpg Moderately hard
- Nashville, TN 77.3 mg/L 4.5 gpg Moderately hard
- Sacramento, CA 83 mg/L 4.9 gpg Moderately hard
- Fresno, CA 89.3 mg/L 5.2 gpg Moderately hard
- Saint Paul, MN 90 mg/L 5 gpg Moderately hard
- Austin, TX 93 mg/L 5.4 gpg Moderately hard
- Washington, DC 95 mg/L 5.6 gpg Moderately hard
- Birmingham, AL 98 mg/L 5.7 gpg Moderately hard
- Kansas City, MO 100 mg/L 5.8 gpg Moderately hard
- Denver, CO 105 mg/L 6.1 gpg Moderately hard
- Tulsa, OK 114.5 mg/L 6.7 gpg Moderately hard
- Louisville, KY 115 mg/L 6.7 gpg Moderately hard
- Columbus, OH 120 mg/L 7 gpg Moderately hard
- Cleveland, OH 120 mg/L 7 gpg Moderately hard
- Philadelphia, PA 125 mg/L 7.3 gpg Hard
- Ann Arbor, MI 126 mg/L 7.4 gpg Hard
- Cincinnati, OH 133 mg/L 7.8 gpg Hard
- Milwaukee, WI 137 mg/L 8.01 gpg Hard
- St. Louis, MO 138 mg/L 8.1 gpg Hard
- Fort Worth, TX 145 mg/L 8.5 gpg Hard
- Honolulu, HI 162.5 mg/L 9.5 gpg Hard
- Wichita, KS 170 mg/L 9.9 gpg Hard
- Omaha, NE 170 mg/L 10 gpg Hard
- Los Angeles, CA 192 mg/L 11.2 gpg Very hard
- Lincoln, NE 192 mg/L 11.2 gpg Very hard
- Tampa, FL 220 mg/L 12.9 gpg Very hard
- Phoenix, AZ 237 mg/L 13.9 gpg Very hard
- Mesa, AZ 239.4 mg/L 14 gpg Very hard
- San Diego, CA 276 mg/L 16 gpg Very hard
- Las Vegas, NV 280 mg/L 16 gpg Very hard
- Chandler, AZ 282.2 mg/L 16.5 gpg Very hard
- San Antonio, TX 299.3 mg/L 17.5 gpg Very hard
- Anaheim, CA 300 mg/L 18 gpg Very hard
- Indianapolis, IN 317 mg/L 19 gpg Very hard
- Madison, WI 324.9 mg/L 19 gpg Very hard
- Scottsdale, AZ 352.5 mg/L 20.6 gpg Very hard
mg/L as calcium carbonate. Each classification band is drawn the same width, so the axis is not linear in mg/L.
Systems with similar published hardness
- Saint Paul, MN Saint Paul Regional Water Services, 90 mg/L (5.3 gpg)
- Austin, TX Austin Water, 93 mg/L (5.4 gpg)
- Washington, DC DC Water, 95 mg/L (5.6 gpg)
- Sacramento, CA City of Sacramento Department of Utilities, 83 mg/L (4.9 gpg)
All 44 verified systems How to find hardness in your own utility's report If you are on a well instead