Maple Grove city water runs about 19 to 22 grains per gallon — roughly 370 parts per million. Water is considered hard above about 7 grains, so this is nearly three times that. The City's own water quality report states that most homes in the community choose to install a private water softener.
Where the number comes from
It comes from the City of Maple Grove's water quality report — the City's own published measurement, not ours. Maple Grove draws from municipal wells rather than a river, which is a large part of why the water is this hard: groundwater picks up calcium and magnesium out of the rock it sits in. The City has treated for iron and manganese since 1987.
Hardness figures can shift year to year as wells and blending change. If you want the current number for your address, pull this year's water quality report from the City rather than trusting a number on any plumber's website — including this one.
How that compares
Text equivalent: soft water is under 1 grain per gallon. Moderately hard is about 3 to 7. Water is considered hard above 7 grains per gallon. Very hard is above roughly 10.5 grains. Maple Grove tap water measures 19 to 22 grains per gallon, about 370 parts per million.
Who else drinks this water
Osseo buys its water from Maple Grove, so an Osseo tap is the same water at the same hardness. Corcoran and part of Dayton are served by the same plant. If you're in one of those places, everything on this page applies to your house.
And if you moved up here from Minneapolis, you noticed the difference in the first week. Minneapolis runs a lime-softened river supply. Coming from that to 20-grain well water is a genuine change in how your soap behaves.
What 20 grains actually does to a house
The honest version, without the scare tactics. Hardness is dissolved calcium and magnesium. Heat it and it comes out of solution as scale, which is why the water heater takes the worst of it: scale builds on the element and settles on the tank bottom, so the heater has to work through an insulating layer to do the same job. More energy in, shorter service life out.
Everywhere else it shows up as the stuff you already recognize. White crust on faucet aerators and shower heads. Glasses that come out of the dishwasher spotted. Film on the shower door that comes back a day after you scrub it. Soap and detergent that won't lather, so you use more of both. Dishwashers and washing machines working harder than they were designed to.
What we won't tell you is exactly how many years of water heater life you're losing — that depends on your tank, your usage and whether anybody has flushed it. And hard water is not a health problem. It's an equipment and household problem.
Is a softener worth it here?
Usually, at this hardness — but it's a math problem, not an article of faith. In the Minneapolis market, installed softeners run roughly $1,000 to $4,000 with an average around $1,572, and you should plan on $100 to $300 a year in salt and maintenance after that.
What you get back is longer life on the water heater, dishwasher and washing machine, fewer cartridge and valve replacements, less soap and detergent, and a house that stops fighting you on the cleaning. At 19–22 grains, most homes here get there.
Who might reasonably skip it: someone in a rental or a short-term stay, someone with very low water use, or someone who simply isn't bothered by spotting and is fine replacing a water heater a little sooner. That's a legitimate choice and we'll say so.
We'd rather you understand the tradeoff than buy a softener because a salesman scared you. Nobody here is paid on commission.
These are Twin Cities metro ranges from public sources, not our prices. What your job costs depends on your house — and you'll have our number before we start.
What about the City's softening study?
The City studied central softening and presented that study to Council in March 2024. Since then it has been surveying residents about it, including in Osseo.
No decision has been made. We're not going to speculate about what the City will do, imply it's happening, or use it as a reason to hurry you into anything. If it changes, the City will say so and we'll update this page.
Well water out west
Corcoran, Greenfield, Independence and rural Dayton are largely on private wells, and well water out there is typically harder than city water. It also brings iron along often enough that we treat it as its own question — iron staining is not a hardness problem and a softener alone frequently won't fix it.
On a well, test before you buy equipment. Sizing a softener to a guess is how people end up with the wrong system and a salt bill for it.
Questions we get about the water
How hard is Maple Grove water?
The City of Maple Grove's water quality report puts hardness at about 19 to 22 grains per gallon, roughly 370 parts per million. Water is generally considered hard above about 7 grains, so this is close to three times that threshold.
Do I need a water softener in Maple Grove?
Most homes here have one — the City's own water quality report states that most homes in the community choose to install a private softener. Whether you need one depends on how much the scale and spotting bother you and how much equipment you want to protect. We'd rather walk you through the tradeoff than sell you one on fear.
Does Osseo have the same water as Maple Grove?
Yes. Osseo buys its water from Maple Grove, so it comes off the same municipal wells at the same hardness. Corcoran and part of Dayton are served by the same plant as well.
How do I test my water hardness?
For city water, start with the current year's water quality report from your city — it's published annually and it's free. If you're on a private well, a lab test is the only reliable answer, and it should check iron and manganese alongside hardness because those need different equipment.
Will a softener make my water taste salty?
A correctly set softener shouldn't. Salt is used to regenerate the resin, not to flavor the water. Salty-tasting water usually means the unit is regenerating improperly or is set for the wrong hardness, and that's a service call, not a reason to skip softening.
Is Maple Grove getting a central softening plant?
No decision has been made. The City studied central softening and presented the study to Council in March 2024, and has been surveying residents about it since. That's the entire status as far as anyone can honestly say — nothing has been approved or scheduled.
Related
Want somebody to look at what the water has done to your equipment?
We'll tell you what's worth doing and what isn't. (763) 342-0801.