Sioux City is, on the public record, the largest municipal water supply in Iowa that does not soften. Roughly 86,000 people, 47 treatment records in the federal inventory, and not one of them is a softening process. What the plants remove is iron and manganese. The hardness goes through.
| Sioux City at a glance | What the record shows |
|---|---|
| Who supplies the water | Sioux City Water Supply, run by the City of Sioux City, PWSID IA9778054, serving 85,791 people in EPA SDWIS against a 2024 Census city estimate of 86,875 |
| Where it comes from | City wells in the Missouri River alluvium and the Dakota sandstone beneath it, at depths from 80 to 320 feet, treated at two plants |
| Softened at the plant | No. The city's own water plant page states that both facilities “use iron and manganese removal as the main treatment process”, and none of the 47 EPA SDWIS treatment records for IA9778054 carries a softening objective |
| Published hardness | 430 and 440 mg/L as calcium carbonate at River Well #12 in June and October 2025, and 520 mg/L at Replacement Well #2 in February 2024 — 25.1 to 30.4 grains per gallon, per the Iowa DNR sample database, analyte 84 |
The city runs the Zenith Water Treatment Plant, rated at 30 million gallons a day, and the Southbridge Regional Water Treatment Plant at 10 million. The published sequence is the same at both: water from the city's wells is aerated, dosed with potassium permanganate in a retention basin for the oxidation of iron and manganese, passed through filters, disinfected with chlorine gas, held in a CT basin, then fluoridated and dosed with phosphate as a corrosion control inhibitor.
Every step there has a purpose, and none of them is calcium and magnesium removal. That is not a criticism of the utility — hardness is not a regulated contaminant and no Iowa city is obliged to remove it. It simply means the mineral load that shows up in the state's well samples is the mineral load arriving at your water heater.
Iowa's drinking water portal holds four hardness results for Sioux City, all taken at wells rather than at a tap: 440 mg/L at River Well #12 on 30 October 2025, 430 mg/L at the same well on 25 June 2025, 520 mg/L at Replacement Well #2 (River 9R) on 28 February 2024, and 520 mg/L at the Southbridge Collector Well #1 in March 2012. Divide by 17.1 and that is roughly 25 to 30 grains per gallon.
Total dissolved solids run alongside it — 690 mg/L at River #12 last October, 790 mg/L at the Southbridge raw tap in April 2025, 920 mg/L at Replacement Well #2. Sodium at the finished-water taps is more moderate: 60 mg/L at the Zenith plant on 2 April 2025 and 70 mg/L at the Southbridge high service tap on 6 January 2025.
Those three numbers together describe the job. High hardness for the softener, high dissolved solids for the drinking water, moderate sodium meaning the city is not adding much of its own.
The Iowa DNR source water records list most of the active Sioux City wells as “Alluvial, Dakota” — the shallow Missouri River sand and gravel and the Dakota sandstone below it, screened together. River Wells #1 and #2 reach 308 and 310 feet, River #11 goes to 315, and the newest, River 2R drilled on 19 July 2024, is a straight Dakota well at 320 feet. Others are far shallower: the Riverfront Collector at 80 feet, the Riverside horizontal well at 88, River #6 at 90.
That range is why a single citywide hardness figure would be misleading even if the city published one. Sioux City does not, and neither will we.
Unsoftened water in the mid-twenties to low-thirties in grains is straightforward softener territory. Every price is all-in: equipment, installation, taxes and a lifetime parts warranty.
Annual maintenance is $199 a year for a tank-RO home and $249 for a tankless-RO home. A full diagnostic service call is $199; a known-issue trip is $99 plus the part. We offer 0% financing, and $100 off for military and first responders. Ask for the written breakdown before you schedule, or start one through our instant quote.
Outside the city system, rural Woodbury County homes tap the same alluvium and Dakota sandstone without the Zenith or Southbridge plants in between — so the iron and manganese the city removes arrive untouched, on top of the hardness. Our well water setup is a dual-tank system at $3,450, or $3,800 with tank RO, with UV disinfection at $700 and sediment pre-filtration at $500 when the readings call for them. We fit tank RO rather than tankless on a well, because high dissolved solids cost a tankless unit its pressure. Start with free well water testing.
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. Installation is handled by licensed local plumbing professionals we vet, schedule and stand behind. Pricing is published and all-in, so the figure you read here is the figure on the paperwork. Distance and site conditions are the only things that can change it, and we tell you before you agree.
Your house sits on one of the biggest unsoftened supplies in the state, and the wells feeding your side of town may not read like the wells feeding the other. We come to you, measure hardness, iron and dissolved solids at your own kitchen sink, and leave you the readings and a written quote at no charge, whichever way you decide. Book your free in-home water test.
Le Mars · Onawa · Sioux Center · Sheldon · Council Bluffs
No. The City of Sioux City's water plant page states that both treatment facilities use iron and manganese removal as the main treatment process, and none of the 47 EPA SDWIS treatment records for PWSID IA9778054 carries a softening objective. The published train is aeration, potassium permanganate, filtration, chlorine gas, a CT basin, fluoride and a phosphate corrosion inhibitor.
The Iowa DNR sample database records 440 mg/L as calcium carbonate at River Well #12 on 30 October 2025, 430 mg/L at the same well on 25 June 2025, and 520 mg/L at Replacement Well #2 on 28 February 2024. That is roughly 25.1 to 30.4 grains per gallon. These are well samples; because the city does not soften, very little of that is removed before it reaches your tap.
Because the wells draw from Missouri River alluvium and Dakota sandstone, which carry a heavy mineral load. The state database records TDS of 690 mg/L at River #12 in October 2025, 790 mg/L at the Southbridge raw tap in April 2025 and 920 mg/L at Replacement Well #2 in 2024. A softener handles hardness; dissolved solids are what reverse osmosis is for.
Sodium measured 60 mg/L at the Zenith plant finished tap on 2 April 2025 and 70 mg/L at the Southbridge high service tap on 6 January 2025, per the Iowa DNR database. That is moderate for Iowa, and it reflects the source rather than the treatment, since Sioux City does not run an ion exchange plant that would add sodium.
A Kind Water Co softener is $2,500, or $2,850 paired with reverse osmosis. The XL softener is $2,800, or $3,150 with RO. Every figure is all-in: equipment, professional installation, taxes and a lifetime parts warranty. Softeners are built from NSF/ANSI 44 certified components and RO systems are certified to NSF/ANSI 58, with 0% financing and $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
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