Water hardness, which is a measure of the concentration of dissolved minerals like calcium and magnesium in water, varies greatly across the geologically diverse terrain of New Hampshire. Located in the New England region of the U.S., New Hampshire features a varied landscape from the White Mountains to the lowland coastal areas and numerous lakes and rivers.
In New Hampshire, water hardness levels can significantly differ from one area to another, influenced by the state’s underlying geology. Much of New Hampshire’s bedrock consists of granite and other igneous and metamorphic rocks that typically contribute less to water hardness. Consequently, areas dominated by granite bedrock, such as regions in central New Hampshire and parts of the White Mountains, may often have softer water because these types of rock are less soluble and less likely to leach minerals into the water.
On the other hand, there are areas in New Hampshire where the water may be harder due to the presence of calcareous materials, limestone, or mineral-rich sediment left by the retreat of glaciers. Water in these locales, potentially including regions along river valleys and basins where glacial and post-glacial deposits are common, may exhibit higher hardness levels due to the minerals that dissolve from these materials into the groundwater supply.
The diversity in water hardness present in New Hampshire not only influences the taste of the water but also impacts the performance of soaps and detergents, and it can lead to scaling in pipes and water heaters. It also has implications for maintaining household appliances and potentially for industrial processes.
The cities listed in this dataset display a range of water hardness levels in New Hampshire, as measured in Parts Per Million (ppm) and Grains Per Gallon (gpg). While the city of Portsmouth has a relatively higher level of hardness at 42.0 ppm (2.5 gpg), others like Manchester and Concord have much softer water, with measurements of 17.9 ppm (1.0 gpg) and 11.5 ppm (0.7 gpg), respectively. The city of Rochester falls in the middle with a hardness level of 25.0 ppm (1.5 gpg). In contrast, Somersworth has a lower level of hardness, at 13.5 ppm (0.8 gpg). Several cities, including Nashua, Dover, Keene, Laconia, Lebanon, Claremont, Berlin, and Franklin, have not provided specific data on water hardness.
| City | Hardness ppm (mg/L) | Hardness gpg | Information Source | Notes |
| Manchester | 17.9 | 1.0 | Link | |
| Nashua | n/a | n/a | Link | Covered by Merrimack Valley (https://www.nashuanh.gov/634/Merrimack-Valley-Water-District) |
| Concord | 11.5 | 0.7 | Link | |
| Dover | n/a | n/a | Link | |
| Rochester | 25.0 | 1.5 | Link | |
| Keene | n/a | n/a | Link | |
| Portsmouth | 42.0 | 2.5 | Link | |
| Laconia | n/a | n/a | Link | |
| Lebanon | n/a | n/a | Link | Mentions they add sodium carbonate for hardness but doesn’t quantify |
| Claremont | n/a | n/a | Link | |
| Somersworth | 13.5 | 0.8 | Link | |
| Berlin | n/a | n/a | Link | |
| Franklin | n/a | n/a | Link |
ppm = Parts Per Million
mg/L = Milligrams Per Liter
gpg = Grains Per Gallon
Hard water can cause issues such as mineral buildup in plumbing and appliances, reduce the efficacy of soaps and detergents, and affect the taste of the water. A tried and true solution is the use of a water softener. A water softener, like the ones from DROP, could be a worthwhile investment.
These devices work by replacing the calcium and magnesium ions that cause hardness with sodium ions, resulting in softer water. With innovative features, easy installation, and efficient operation, DROP smart water softeners provide a solution to hard water issues, extending the lifespan of appliances, improving water taste, enhancing soap effectiveness, reducing scale build-up, and increasing the overall water efficiency in your home.
