Carroll's water is unusually clean and unusually hard, and both come from the same place. The city sits on Dakota Sandstone, a Cretaceous aquifer found in only a handful of Iowa counties, which its own report describes as not susceptible to contamination. That protection does nothing about minerals: 402 mg/L of hardness reaches every tap in town.
| Carroll at a glance | What the record shows |
|---|---|
| Who supplies the water | Carroll Municipal Water Supply, run by the Carroll Water Department, PWSID IA1415072, 10,184 people served (EPA SDWIS); 2024 Census city estimate 10,125 |
| Where it comes from | The Dakota Sandstone aquifer. The city's Consumer Confidence Report notes the aquifer is not susceptible to contamination because the overlying materials block surface contaminants |
| Softened at the plant | No. The city's own report lists treatment in full: “aeration to oxidize iron, filtration to remove iron and manganese, disinfection to kill bacteria, fluoridation to aid in the prevention of tooth decay and orthophosphate to provide corrosion control treatment.” EPA SDWIS agrees — no softening objective in twenty-two treatment records |
| Published hardness | 402 mg/L as calcium carbonate (23.5 grains per gallon) at the source entry point serving Wells #12, 14, 16, 17, 18 and 19, sampled 04/11/2022; 370 mg/L at the new well site in 2020; 390 to 430 mg/L at Wells #18 and #19 in 2015 (Iowa DNR Drinking Water Portal) |
Carroll's report makes a genuinely good point about its source: the geology above the Dakota Sandstone blocks surface contaminants, which is why the city can list a short, simple treatment train and mean it. Sodium is 12.7 mg/L and arsenic 1.60 parts per billion, both low. This is well-protected water.
None of that touches hardness, because hardness is dissolved rock rather than contamination. Sandstone aquifers hand you calcium and magnesium by definition, and the treatment Carroll runs — aeration, filtration, disinfection, fluoride and orthophosphate — is aimed at iron, bacteria and corrosion control. There is no step in that list that removes a mineral. So a Carroll household at 23.5 grains per gallon is entirely on its own for softening, in water that is otherwise in very good shape.
That combination actually makes the equipment decision simpler than it is in most towns. There is no nitrate story here, no radium story, no chloramine to size a carbon stage around. Our guide to how hard Iowa water is sets 23.5 grains in context, and Atlantic, the other Dakota-aquifer town on this site, tells a related story at a lower number.
Aeration first, then filtration for iron and manganese, tells you what comes up the well. Iron is what stains a toilet tank orange and puts rust-coloured marks on white laundry, and it is also what coats softener resin and quietly costs a unit its rated capacity. In a town with 23.5 grains to remove and iron in the source, a softener has two jobs at once and needs to be specified with both readings in hand. Our note on orange staining covers what iron looks like in a house.
The 402 mg/L figure came from the source entry point serving six wells at once — #12, 14, 16, 17, 18 and 19 — which makes it a blended reading rather than any single well's. Individual wells told a wider story: 390 to 430 mg/L at Wells #18 and #19 back in 2015, and 370 at the new well site in 2020.
That 60 mg/L spread across the field is worth about 3.5 grains per gallon, which is a real difference when you are sizing equipment. Which wells are carrying the load on a given day depends on demand and on maintenance, so the blend that reaches a house in July is not necessarily the blend that reaches it in February.
The pattern is also reassuring in one way: after ten years of sampling, every result sits between 370 and 430. Carroll's water is hard, consistently, and it is not drifting.
All prices are all-in: equipment, installation, taxes and a lifetime parts warranty.
Maintenance plans are $199 a year for a tank-RO home and $249 a year for a tankless-RO home. Diagnostic service calls are $199; a known-issue trip is $99 plus the part. There is 0% financing, and $100 off for military and first responders. Ask for the full written breakdown before booking, or start one at our instant quote.
Beyond the city, rural Carroll County homes tap the same Dakota Sandstone without the aeration and filtration step, so iron arrives with the hardness and nothing disinfects it. 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. We fit tank RO rather than tankless on a well, because high dissolved solids cost a tankless unit its pressure.
We are 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 do the installing. Every price is published and all-in, and we would rather test your water and tell you that you need less than you expected.
Carroll's published figures span 370 to 430 mg/L across several wells and a decade of sampling, and which well is feeding your street changes with demand. A reading at your own tap settles it. We test hardness, iron and the rest, and leave you the numbers and a written quote at no charge. Book your free in-home water test.
Atlantic · Ames · Winterset · Des Moines
The Iowa DNR sample database recorded 402 mg/L as calcium carbonate — 23.5 grains per gallon — at the source entry point serving Wells #12, 14, 16, 17, 18 and 19 on 11 April 2022, with a 2015 to 2022 range of 370 to 430 mg/L. Carroll does not soften, so that reaches your tap untouched.
No. The city's own Consumer Confidence Report lists its treatment in full as “aeration to oxidize iron, filtration to remove iron and manganese, disinfection to kill bacteria, fluoridation to aid in the prevention of tooth decay and orthophosphate to provide corrosion control treatment.” EPA SDWIS holds twenty-two treatment records with no softening objective.
A Cretaceous aquifer found in only a handful of Iowa counties, and Carroll's source. The city's report notes it is not susceptible to contamination because the overlying materials block surface contaminants. That protection keeps sodium at 12.7 mg/L and arsenic at 1.60 parts per billion, but it does nothing about dissolved minerals.
Because hardness is dissolved rock, not contamination. Sandstone aquifers hand you calcium and magnesium by definition, and nothing in Carroll's treatment train — aeration, filtration, disinfection, fluoride and orthophosphate — removes a mineral. Protected water and hard water are entirely compatible.
A Kind Water Co softener is $2,500 all-in, covering equipment, installation, taxes and a lifetime parts warranty, or $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.
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