Grinnell has one of the hardest published water figures in central Iowa and no softening step anywhere in its plant. The Iowa DNR sample database recorded 490 mg/L as calcium carbonate at Grinnell Well #10 on 1 July 2025 — 28.7 grains per gallon — and every treatment record the city holds is for aeration, chlorination or corrosion control.
| Grinnell at a glance | What the record shows |
|---|---|
| Who supplies the water | Grinnell Water Department, PWSID IA7930008, 9,564 people served (EPA SDWIS); 2024 Census city estimate 9,495 |
| Where it comes from | Jordan sandstone wells. EPA SDWIS holds only six treatment entries in total for this system: phosphate corrosion inhibitor, hypochlorite chlorination, and forced-draft aeration |
| Softened at the plant | No. There is no softening objective of any kind in the SDWIS record, and the city's own report confirms its treatment does not address hardness |
| Published hardness | 490 mg/L as calcium carbonate (28.7 grains per gallon) at Well #10 on 07/01/2025, 390 mg/L at the same well on 04/10/2025, and 358 to 369 mg/L across Wells #8, #9 and the source entry point in 2022 (Iowa DNR Drinking Water Portal, analyte 84) |
Seven samples between 2022 and 2025 put Grinnell's water between 358 and 490 mg/L. Even the lowest of those is about 21 grains per gallon; the highest is nearly 29. For scale, most softener manufacturers class anything over 10.5 grains as “very hard,” and Grinnell is running at two to three times that.
You do not need a lab to see it at that level. It is the white crust on a kettle element, the film that will not come off shower glass, the towels that come out of the wash stiff, and a water heater that loses a little efficiency every year to scale on the element. Our note on what limescale does to appliances covers the mechanics, and our signs you need a softener guide is a fair checklist.
Grinnell is one of the strongest cases for a whole-home softener anywhere in the state, and the sizing needs to reflect the actual number rather than a regional average. A unit specified for 15 grains in a 28-grain town will regenerate constantly and wear out early.
Grinnell has been above the federal maximum contaminant level for combined radium, 226 and 228, continuously since early 2024. The city has issued public notifications for the fourth quarter of 2025 and the first quarter of 2026 confirming the system still exceeds the 5 pCi/L standard, and it states plainly that its current plant “does not have the capability to remove radium.” A new treatment plant is not expected to come online until January 2027.
That is the record as the City of Grinnell publishes it, and residents should read the city's own notices for the current status rather than take a treatment company's word for anything. What we can add is the equipment fact: reverse osmosis is a recognised point-of-use treatment technology for dissolved radionuclides, and it is what a Grinnell household would use at the kitchen tap while the city builds. Our RO systems are certified to NSF/ANSI 58.
Sodium is worth knowing too: 130 mg/L on 1 July 2025, with an older city report listing 220 ppm. Sodium is not a regulated contaminant and no limit is printed beside it, but it is another thing reverse osmosis addresses at the point of use.
Grinnell is a two-part job for most households: soften the whole house, treat the drinking water separately. Every price is all-in: equipment, installation, taxes and a lifetime parts warranty.
Annual maintenance runs $199 a year for a tank-RO home and $249 a year for a tankless-RO home. A full diagnostic service call is $199; a known-issue trip is $99 plus the part. Financing is 0%, and military and first responders take $100 off. Ask for the written breakdown up front, or start one from our instant quote.
Outside the city, rural Poweshiek County homes sit on private wells with no aeration, no chlorination and no annual report behind them. Our well water system is a dual-tank build at $3,450, or $3,800 with tank RO, plus UV disinfection at $700 and sediment pre-filtration at $500 where the test calls for them. On a well we always fit a tank RO rather than a tankless unit, because high dissolved solids cost a tankless system its pressure. Begin with free well water testing.
Kind Water Co is licensed and insured, and our softeners are built from NSF/ANSI 44 certified components and our reverse osmosis systems are certified to NSF/ANSI 58. Licensed local plumbing professionals we vet, schedule and stand behind carry out every install. Our pricing is published, all-in and the same for every household, so nothing new appears once someone is in your basement.
Grinnell's published range runs from 358 to 490 mg/L across four sampling points, which is a wide spread to size equipment from. Fifteen minutes at your own sink turns it into one number. We test hardness, iron and the rest, and leave you the readings and a written quote whether or not you buy. Book your free in-home water test.
Newton · Marshalltown · Knoxville · Ames · Des Moines
The Iowa DNR sample database recorded 490 mg/L as calcium carbonate — 28.7 grains per gallon — at Grinnell Well #10 on 1 July 2025, 390 mg/L at the same well in April 2025, and 358 to 369 mg/L across Wells #8, #9 and the source entry point in 2022. Grinnell does not soften, so that arrives at your tap untouched.
No. EPA SDWIS holds only six treatment records for PWSID IA7930008 — phosphate corrosion inhibitor, hypochlorite chlorination and forced-draft aeration. There is no softening objective of any kind, and the city's own report confirms its treatment does not address hardness.
The city states it has been above the federal maximum contaminant level for combined radium 226 and 228 continuously since early 2024, with public notifications issued for the fourth quarter of 2025 and the first quarter of 2026 confirming the system still exceeds the 5 pCi/L standard. Grinnell says its current plant “does not have the capability to remove radium” and expects a new plant in January 2027.
A larger one than a regional average would suggest. Capacity is consumed in proportion to grains removed, so a unit sized for 15 grains in a 28-grain town regenerates far more often and wears out sooner. That is why we size from a measured reading at your own tap, and why the XL build is worth pricing in a larger Grinnell household.
A Kind Water Co softener is $2,500 all-in, covering equipment, installation, taxes and a lifetime parts warranty, and $2,850 paired with reverse osmosis. The XL build is $2,800, or $3,150 with RO. Softeners use NSF/ANSI 44 certified components and RO systems are certified to NSF/ANSI 58. Financing is 0%, with $100 off for military and first responders.
Every number on this page comes from a public record. Here is where to open each one yourself.
Whole-home water softening, filtration, and reverse-osmosis drinking water — professionally installed and built to last a lifetime.
Serving Marion, Cedar Rapids & surrounding Linn County communities
Kind Water Co is a d/b/a of Zero Cap Investments LLC · 2258 Bison St, Apt B, Marion, IA 52302
.webp)
