Water hardness in Lake Forest Park
5.9 gpg moderately hard
Tap water in Lake Forest Park is moderately hard: 5.9 gpg (101 mg/L · 5.7 °dH · 10.1 °fH).
Source: Lake Forest Park Water District: Our Water, Water Quality Summary (2019) · data checked 2026-10-29
This figure is over 3 years old; hardness may have changed.
Lake Forest Park is served partly by the Lake Forest Park Water District, which uses wells, and partly by Seattle Public Utilities. The district's water quality summary reports 101.1 mg/L as CaCO₃, a moderately hard value. That figure applies to the district's wells, so addresses on Seattle's supply may see different numbers.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 5.9 gpg |
|---|---|
| Utility | Lake Forest Park Water District (wells; part of city served by Seattle Public Utilities) |
How Lake Forest Park compares
- Tap water in Lake Forest Park is 35 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1011 of 1372 in the United States (1 = hardest); 26 % of these cities have softer water.
- In Washington it is number 7 of 27 cities; the regional median is 2.8 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 Lake Forest Park
| 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 Lake Forest Park water hard or soft?
It is moderately hard: 101 mg/L as CaCO₃ (5.9 gpg, 5.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Lake Forest Park 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 Lake Forest Park water?
5.9 gpg, equal to 5.7 °dH, 10.1 °fH or 101 mg/L calcium carbonate.
What dishwasher salt setting should I use in Lake Forest Park?
For 101 mg/L (5.7 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Lake Forest Park?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Lake Forest Park Water District: Our Water, Water Quality Summary (2019). Method: figure published by the water supplier. Lake Forest Park Water District: Our Water, Water Quality Summary · Outdated figure? Tell us