Quick answer: Hard water carries dissolved minerals, mainly calcium and magnesium. USGS classifies water as soft up to 60 mg/L (as calcium carbonate), moderately hard at 61 to 120, hard at 121 to 180, and very hard above 180. It is not a health hazard, but it leaves scale in pipes, fixtures and water heaters and makes soap work less well. Soquel Creek Water District describes its water as hard to very hard. If you treat it with a softener and your home is on septic, the county does not allow softener discharge into the septic system.
What makes water hard
As water moves through soil and rock it dissolves minerals. USGS identifies calcium and magnesium as the main contributors to hardness. How much your water picks up depends on the geology around your water source, so hardness varies from one district, and even one well, to the next.
How hardness is measured
Hardness is reported as calcium carbonate, in milligrams per liter (mg/L), parts per million (ppm) or grains per gallon (gpg). One grain per gallon equals 17.1 mg/L.
| Classification (USGS) | mg/L as calcium carbonate |
|---|---|
| Soft | 0 to 60 |
| Moderately hard | 61 to 120 |
| Hard | 121 to 180 |
| Very hard | More than 180 |
How hard is water in Santa Cruz County?
It depends on your provider. Soquel Creek Water District, which serves Capitola, Soquel, Aptos and La Selva Beach, publishes these ranges from 2017 data:
- Capitola and Soquel (41st Avenue to Park Avenue): about 150 to 370 ppm
- Soquel and Aptos (Park Avenue to State Park Drive): about 140 to 300 ppm
- Aptos and Rio del Mar (State Park Drive to Mar Monte Avenue): about 150 to 200 ppm
- La Selva Beach: about 100 to 200 ppm
Other providers list hardness in their annual water quality report, called a Consumer Confidence Report. You can find yours through your provider or EPA's Consumer Confidence Report page. On a private well, a water test is the only way to know.
What hard water does in your home
USGS links hardness to scale on equipment and to needing more soap and detergent. In practice that shows up as:
- Scale on fixtures and shower glass, the white crust left when water evaporates.
- Scale in water heaters, where minerals settle as sediment. Our water heater repair or replace guide covers water heater upkeep.
- Clogged aerators and showerheads, which slowly lose flow.
- Spots on dishes and soap scum, because soap reacts with the minerals instead of lathering.
Both USGS and Soquel Creek Water District note that hardness itself is not a health hazard.
Treatment options
- Do nothing and clean regularly. For moderately hard water, descaling aerators, showerheads and fixtures and flushing the water heater may be enough.
- Ion exchange water softener. Swaps calcium and magnesium for sodium or potassium. Soquel Creek Water District notes that EPA recommends choosing a softener certified by NSF International, UL or the Water Quality Association. Regeneration produces salty brine that has to go somewhere.
- Salt-free conditioners. These do not remove minerals; they are marketed to reduce scale. Our softener versus conditioner comparison covers the tradeoffs.
If your home is on septic
Santa Cruz County's sewage disposal ordinance says discharge from water softeners and drinking water filters shall not go to the septic system, and County Environmental Health warns that softener brine can harm tank bacteria and clog the leach field. Plan an approved discharge arrangement with County Environmental Health before installing a softener on a septic property. Homes on sewer discharge through the sewer connection.
Frequently asked questions
Is hard water safe to drink?
USGS says the minerals that cause hardness are not toxic, and Soquel Creek Water District says hard water is not a health hazard.
How do I find out how hard my water is?
Check your provider's annual Consumer Confidence Report or website. On a private well, have the water tested.
Do I need a water softener?
Not always. It depends on how hard your water is, how much scale bothers you, and whether you are on septic. For many homes with moderately hard water, regular descaling is enough.
Sources
- USGS, Do you have information about water hardness in the United States?
- Soquel Creek Water District, Water Hardness
- U.S. EPA, Consumer Confidence Reports
- Santa Cruz County Environmental Health, The Harmful Effects of Water Softener Discharge on Your Septic System
- Santa Cruz County Local Agency Management Program, Appendix A: Sewage Disposal Ordinance
Need help with hard water?
Wade's Plumbing & Septic handles water softener maintenance and water filtration installation across Santa Cruz County and nearby Santa Clara County communities. Quotes are free and pricing is flat rate, quoted on site before work begins. Request service or call during office hours, Monday to Friday, 9:00 AM to 5:00 PM.
