Water Hardness

Water Hardness

Depending on the supply source, the water you use can be hard or soft. Ground water makes up almost 61% of the District’s supply. Water from our 11 production wells has an average hardness of 94 Milligrams per Liter (or parts per million). Water from the City of Everett, which makes up the other 39% is soft. Refer to our Water Quality Reports to find your specific source data.

Minerals like calcium and magnesium in the water are responsible for its hardness. The U.S. Geological Survey defines hardness by measuring the calcium carbonate in the water in parts per million (ppm). Water with more than 60 parts per million of the compound is considered hard.

Water from a deep underground aquifer is usually hard. It is in contact with layers of rock formations and mineral deposits. For that reason, well water tends to be hard and water from lakes, rivers and streams tends to be soft. The hardness has minimal fluctuation between samples, but the numbers do change from sample to sample.

Water Hardness Scale

Grains Per GallonMilligrams Per Liter (mg/L) or Parts Per Million (ppm)ClassificationWater Source
Less than 1.0Less than 17.1SoftCity of Everett
1.0 to 3.517.1 to 60Slightly HardCross Valley
3.5 to 7.060 to 120Moderately HardCross Valley
7.0 to 10.5120 to 180Hard N/A
Over 10.5Over 180Very Hard N/A