Water hardness in Southfield
6.1 gpg moderately hard
Tap water in Southfield is moderately hard: 6.1 gpg (105 mg/L · 5.9 °dH · 10.5 °fH).
Source: City of Southfield 2025 Consumers Annual Report on Water Quality (2025) · data checked 2026-10-20
Range across supply zones: 96–130 mg/L.
3 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| GLWA Lake Huron plant tap | 6.1 | 105 | moderately hard |
| GLWA Northeast plant (Detroit River) tap | 6.1 | 105 | moderately hard |
| GLWA Springwells plant (Detroit River) tap | 6.2 | 106 | moderately hard |
Southfield buys treated water through SOCWA from the Great Lakes Water Authority. Its 2025 report lists three plants: Springwells at 106 mg/L (range 97 to 130), Northeast at 105 mg/L (96 to 120) and Lake Huron at 105 mg/L (96 to 130). The report does not say which plant serves which address, so we show the range. The three figures are close, and the difference between plants is small.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 6.1 gpg |
|---|---|
| Utility | City of Southfield (water bought via SOCWA from GLWA) |
How Southfield compares
- Tap water in Southfield is 32 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 988 of 1372 in the United States (1 = hardest); 28 % of these cities have softer water.
- In Michigan it is number 15 of 28 cities; the regional median is 6.2 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Southfield
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 6 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Southfield water hard or soft?
It is moderately hard: 105 mg/L as CaCO₃ (6.1 gpg, 5.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Southfield safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Southfield water?
6.1 gpg, equal to 5.9 °dH, 10.5 °fH or 105 mg/L calcium carbonate.
What dishwasher salt setting should I use in Southfield?
For 105 mg/L (5.9 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Southfield?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: City of Southfield 2025 Consumers Annual Report on Water Quality (2025). Method: figure published by the water supplier. City of Southfield 2025 Consumers Annual Report on Water Quality · Outdated figure? Tell us