Hard water by city
This table lists drinking water hardness for 45 U.S. cities exactly as each utility publishes it, with the period it covers and a link to the source. The U.S. Geological Survey classes water above 180 mg/L as calcium carbonate as very hard and 60 mg/L or less as soft. One grain per gallon is about 17.1 mg/L.
Download: cities.json. Utility figures describe a whole system; water at one address can differ.
| City | Utility and measure | As published | Period and source | Checked |
|---|---|---|---|---|
| Chandler, AZ | City of Chandler: Total hardness | 173-288 mg/L (10.1-16.8 grains per gallon) | Calendar year 2025, source | 2026-10-26 |
| Gilbert, AZ | Town of Gilbert: Total hardness | Average 10.79 grains per gallon (184.44 mg/L), range 6.61-17.54 grains per gallon | Calendar year 2025, source | 2026-10-26 |
| Mesa, AZ | City of Mesa: Average hardness, City Zone | About 12 grains per gallon | Calendar year 2025, source | 2026-10-26 |
| City of Mesa: Average hardness, Eastern and Southern Zones | 16 grains per gallon | Calendar year 2025, source | ||
| Phoenix, AZ | City of Phoenix: Total hardness | 172-302 ppm (10-17.6 grains per gallon), range only | Calendar year 2025, source | 2026-10-26 |
| Scottsdale, AZ | City of Scottsdale: Approximate hardness, south of Indian School Rd | 13-15 grains per gallon (230-260 mg/L) | Calendar year 2025, source | 2026-10-26 |
| City of Scottsdale: Approximate hardness, Indian School Rd to Chaparral Rd | 13-17 grains per gallon (215-285 mg/L) | Calendar year 2025, source | ||
| City of Scottsdale: Approximate hardness, north of Chaparral Rd | 13-17 grains per gallon (230-290 mg/L) | Calendar year 2025, source | ||
| Tucson, AZ | Tucson Water: Hardness, as Tucson Water describes it | "Hard to very hard" (no number given) | Undated document, source | 2026-10-27 |
| Los Angeles, CA | LADWP: Total hardness, Los Angeles Aqueduct plant | Average 103 mg/L, range 96-117 mg/L | Calendar year 2025, source | 2026-10-27 |
| LADWP: Total hardness, northern wells | Average 115 mg/L, range 78-151 mg/L | Calendar year 2025, source | ||
| LADWP: Total hardness, southern wells | Average 116 mg/L, range 83-159 mg/L | Calendar year 2025, source | ||
| LADWP: Total hardness, MWD Weymouth plant | Average 234 mg/L, range 189-280 mg/L | Calendar year 2025, source | ||
| LADWP: Total hardness, MWD Diemer plant | Average 236 mg/L, range 191-280 mg/L | Calendar year 2025, source | ||
| LADWP: Total hardness, MWD Jensen plant | Average 140 mg/L, range 137-142 mg/L | Calendar year 2025, source | ||
| Riverside, CA | Riverside Public Utilities: Hardness | Average 197 mg/L (12 grains per gallon), range 180-210 mg/L | Calendar year 2025, source | 2026-10-27 |
| San Diego, CA | City of San Diego Public Utilities: Total hardness, Alvarado plant | Average 237 ppm (13.8 grains per gallon), range 203-270 ppm | Calendar year 2025, source | 2026-10-27 |
| City of San Diego Public Utilities: Total hardness, Miramar plant | Average 242 ppm (14.1 grains per gallon), range 200-285 ppm | Calendar year 2025, source | ||
| City of San Diego Public Utilities: Total hardness, Otay plant | Average 243 ppm (14.2 grains per gallon), range 201-271 ppm | Calendar year 2025, source | ||
| City of San Diego Public Utilities: Total hardness, purchased treated water | Average 145 ppm (8.5 grains per gallon), range 54.4-232 ppm | Calendar year 2025, source | ||
| San Francisco, CA | SFPUC: Hardness | Average 62 ppm, range 8.1-112 ppm | Calendar year 2025, source | 2026-10-27 |
| Denver, CO | Denver Water: Total hardness | Average 105,009 ppb, range 55,000-124,000 ppb | Calendar year 2025, source | 2026-10-27 |
| Denver Water: Hardness, as Denver Water describes it | "Soft to moderately hard" | Undated web page, source | ||
| Washington, DC | DC Water: Total hardness | Average 139 ppm (8 grains per gallon), range 84-194 ppm | Calendar year 2025, source | 2026-10-27 |
| Jacksonville, FL | No published hardness figure found | 2026-10-27 | ||
| Miami, FL | No published hardness figure found | 2026-10-27 | ||
| Orlando, FL | OUC: Total hardness | Average 129 ppm (7 grains per gallon) | Undated web page, source | 2026-10-27 |
| Tampa, FL | Tampa Water Department: Total hardness | Average 185 mg/L (10.8 grains per gallon) | Calendar year 2024, source | 2026-10-27 |
| Tampa Water Department: Hardness through the year | About 140-300 ppm (8-17 grains per gallon) | Undated document, source | ||
| Atlanta, GA | No published hardness figure found | 2026-10-27 | ||
| Chicago, IL | Chicago Department of Water Management: Hardness as CaCO3, quarterly samples at both plants | 129 to 158 mg/L | Three 2014 quarterly samplings (March, June and August 2014), source | 2026-10-27 |
| Indianapolis, IN | Citizens Energy Group: Hardness | Average 317 ppm (19 grains per gallon), range 148-460 ppm | Calendar year 2025, source | 2026-10-27 |
| Boston, MA | MWRA (for Boston Water and Sewer Commission): Typical total hardness | Approximately 16 mg/L, or 1 grain per gallon | Undated web page, source | 2026-10-27 |
| MWRA (for Boston Water and Sewer Commission): Total hardness, monthly reading | 14.3 mg/L at the Carroll Water Treatment Plant | July 2026 sampling, source | ||
| Baltimore, MD | Baltimore City DPW (Montebello laboratory): Hardness, annual average of monthly results | 114 mg/L (monthly range 109-120) | Calendar year 2022, source | 2026-10-27 |
| Baltimore City DPW (Ashburton laboratory): Hardness, annual average of monthly results | 80 (monthly range 76-84; the form prints no unit) | Calendar year 2022, source | ||
| Detroit, MI | Detroit Water and Sewerage Department: Total hardness | Average 107 ppm, range 96-142 ppm | Calendar year 2025, source | 2026-10-27 |
| Minneapolis, MN | Minneapolis Water Treatment and Distribution: Total hardness, plant effluent | Average 94 ppm, range 80-113 ppm | Calendar year 2025, source | 2026-10-27 |
| St. Louis, MO | City of St. Louis Water Division: Total hardness | Average 129 ppm, range 80-206 ppm | Calendar year 2025, source | 2026-10-27 |
| Kansas City, MO/KS | BPU (Kansas City, KS): Total hardness | 280 ppm (16.4 grains per gallon) | Jan.-Dec. 2025, source | 2026-10-26 |
| WaterOne (Johnson County, KS): Total hardness | Average 135 ppm, range 110-157 ppm | Calendar year 2025, source | ||
| Independence, MO: Total hardness | 123 mg/L as calcium carbonate (single sample) | Sampled May 6, 2024, source | ||
| KC Water (Kansas City, MO): Average hardness | 100 mg/L (5-6 grains per gallon) | Undated web page, source | ||
| Charlotte, NC | Charlotte Water: Total hardness | Average 32 ppm, range 27-35 ppm | Calendar year 2025, source | 2026-10-27 |
| Jersey City, NJ | Veolia Jersey City: Hardness (as calcium carbonate) | Range 62-103 ppm | Calendar year 2022, source | 2026-10-27 |
| Henderson, NV | City of Henderson: Hardness | Typically 304 parts per million (18 grains per gallon) | 2026 report (2025 data), source | 2026-10-26 |
| Las Vegas, NV | Las Vegas Valley Water District: Hardness | 280 parts per million (16 grains per gallon) | Calendar year 2025, source | 2026-10-26 |
| New York City, NY | NYC DEP: Total hardness | Average 32 mg/L (2 grains per gallon), range 18-100 mg/L | Calendar year 2025, source | 2026-10-27 |
| Cincinnati, OH | Greater Cincinnati Water Works: Average hardness, Miller Plant | Average 126 mg/L (7 grains per gallon) | Undated FAQ on the page for the 2025 report, source | 2026-10-27 |
| Greater Cincinnati Water Works: Average hardness, Bolton Plant | Average 140 mg/L (8 grains per gallon) | Undated FAQ on the page for the 2025 report, source | ||
| Oklahoma City, OK | No published hardness figure found | 2026-10-27 | ||
| Allentown, PA | Lehigh County Authority: Total hardness | Average 15.0 grains per gallon, range 10.5-16.6 grains per gallon | Calendar year 2025, source | 2026-10-27 |
| Philadelphia, PA | Philadelphia Water Department: Hardness, Baxter plant | Average 101 ppm (6 grains per gallon), range 72-121 ppm | 2025 report year, source | 2026-10-27 |
| Philadelphia Water Department: Hardness, Belmont plant | Average 151 ppm (9 grains per gallon), range 99-204 ppm | 2025 report year, source | ||
| Philadelphia Water Department: Hardness, Queen Lane plant | Average 169 ppm (10 grains per gallon), range 119-270 ppm | 2025 report year, source | ||
| Pittsburgh, PA | Pittsburgh Water: Hardness, as Pittsburgh Water describes it | "Moderately hard" (no number given) | Undated web page, source | 2026-10-27 |
| Nashville, TN | Metro Water Services: Total hardness | 100.5 mg/L, range 88.5-128.4 mg/L | 2023 data, in the 2025 report, source | 2026-10-27 |
| Metro Water Services: Calcium hardness | 75.3 mg/L, range 63.9-92.6 mg/L | Undated row, 2025 water quality report, source | ||
| Austin, TX | Austin Water: Total hardness | Average 93 ppm (5.4 grains per gallon), range 70-126 ppm | Calendar year 2025, source | 2026-10-27 |
| Dallas, TX | Dallas Water Utilities: Total hardness | Average 119 mg/L, range 92-167 mg/L | Calendar year 2003, source | 2026-10-27 |
| Fort Worth, TX | Fort Worth Water: Total hardness as CaCO3 | 76.5 to 175 ppm (5 to 10 grains per gallon), range only | Calendar year 2024, source | 2026-10-27 |
| Houston, TX | Houston Public Works: Total hardness, main system | Average 135.5 ppm, range 43.5-229 ppm | Calendar year 2025, source | 2026-10-27 |
| McAllen, TX | No published hardness figure found | 2026-10-27 | ||
| New Braunfels, TX | New Braunfels Utilities: Water hardness range | 13.7 to 17.4 grains per gallon, described as "very hard" | Undated web page (the same range appears as 2017 data in NBU's 2018 report), source | 2026-10-27 |
| San Antonio, TX | San Antonio Water System: Typical hardness | 15 to 20 grains per gallon | Undated FAQ page, source | 2026-10-26 |
| Seattle, WA | Seattle Public Utilities: Hardness, Cedar distribution sample | 1.55 grains per gallon | Single sample, May 2026, source | 2026-10-27 |
| Seattle Public Utilities: Hardness, Tolt distribution sample | 1.53 grains per gallon | Single sample, May 2026, source | ||
| Madison, WI | Madison Water Utility: Hardness, citywide | 18-20 grains per gallon | Undated FAQ, source | 2026-10-27 |
| Madison Water Utility: Hardness, Unit Well 6 | 450 mg/L (26 grains per gallon) | Calendar year 2025, source | ||
| Madison Water Utility: Hardness, Unit Well 14 | 580 mg/L (34 grains per gallon) | Calendar year 2025, source | ||
By state
Arizona: Chandler (hard to very hard), Gilbert (moderately hard to very hard), Mesa (very hard), Phoenix (hard to very hard), Scottsdale (very hard), Tucson
California: Los Angeles (moderately hard to very hard), Riverside (hard to very hard), San Diego (soft to very hard), San Francisco (soft to moderately hard)
Colorado: Denver (soft to hard)
District of Columbia: Washington (moderately hard to very hard)
Florida: Jacksonville, Miami, Orlando (hard), Tampa (hard to very hard)
Georgia: Atlanta
Illinois: Chicago (hard)
Indiana: Indianapolis (hard to very hard)
Massachusetts: Boston (soft)
Maryland: Baltimore (moderately hard)
Michigan: Detroit (moderately hard to hard)
Minnesota: Minneapolis (moderately hard)
Missouri: St. Louis (moderately hard to very hard)
Missouri and Kansas: Kansas City (moderately hard to very hard)
North Carolina: Charlotte (soft)
NJ: Jersey City (moderately hard)
Nevada: Henderson (very hard), Las Vegas (very hard)
New York: New York City (soft to moderately hard)
Ohio: Cincinnati (hard)
Oklahoma: Oklahoma City
Pennsylvania: Allentown (hard to very hard), Philadelphia (moderately hard to very hard), Pittsburgh
Tennessee: Nashville (moderately hard to hard)
Texas: Austin (moderately hard to hard), Dallas (moderately hard to hard), Fort Worth (moderately hard to hard), Houston (soft to very hard), McAllen, New Braunfels (very hard), San Antonio (very hard)
Washington: Seattle (soft)
Wisconsin: Madison (very hard)