Overland Park's water is built to deposit scale, pH 9.1 to 9.6 with a saturation index of +0.79 to +1.4, and hardness moves from 119 to 172 mg/L.
Overland Park's water is hard and built to deposit scale, with WaterOne running it strongly alkaline to protect pipes, so it leaves a stubborn film wherever it dries on glass. July to September is the dependable window, and south-facing upper walls add height to many jobs. High pane counts and premium homes put prices at the top of the Kansas range, $290 to $470 for a single-story exterior.
Published, current, and unusually complete. WaterOne reports total hardness as calcium carbonate averaging 144 mg/L with a 119 to 172 range for 2024, plus calcium hardness at 88 mg/L, calcium 37 and magnesium 14. The range is real and mechanical: lime and sometimes soda ash are dosed according to the raw river profile, so the degree of softening moves with the source. Read the figure next to the pH of 9.6 and the positive saturation index — this is intentionally mineral-depositing water, so the practical problem is film rather than scale, and it is alkaline film.
| Hardness | 144 mg/L as CaCO₃ Hard, as published by WaterOne. |
|---|---|
| pH | 9.1–9.6 |
| Alkalinity | 46–61 mg/L as CaCO₃ |
| Corrosion index | Langelier index +0.79 to +1.4 |
| Sodium | 44–62 mg/L |
| Chloride | 24–47 mg/L |
| Disinfectant | ozone + chloramine |
| Source and treatment | The Kansas and Missouri Rivers and adjacent collector wells, in the utility's own words · Microscreening, rapid mix, coagulation and flocculation, lime and soda ash softening with sedimentation and follow-up filtration, rapid sand filtration, ozonation, pH adjustment and fluoridation, with monochloramine carried as the distribution residual · The plant softens. |
Not in the report: iron, manganese and total dissolved solids.
SOURCE · WaterOne 2026 KDHE Consumer Confidence Report (PWS KS2009110), with WaterOne's own treatment pages and the EPA SDWIS federal treatment record · How we source these numbers
Mineral film is the year-round constant and is worst in hot, sunny, dry conditions where rinse water flashes off before it can be pulled. Hardness itself drifts across the 119 to 172 band with river conditions. Organic load follows the Kansas City metro calendar — tree pollen late February through May, grass into June, ragweed from August to the first hard frosts. Storm debris and hail damage cluster in May and June. The wash that holds best is after the first frosts; the worst value is mid-September into combined ragweed and mould.
KANSAS SEASON BY SEASON →Overland Park drinks WaterOne's water, and WaterOne documents it better than almost any utility on this site: total hardness 144 mg/L as calcium carbonate in 2024, range 119 to 172. The number that actually governs the work is the pH of 9.1 to 9.6 combined with a positive saturation index of 0.79 to 1.4 — WaterOne says outright that it designs its chemistry to micro-deposit calcium and magnesium as a protective pipe coating. Water built to deposit minerals deposits them on glass, as an alkaline film that an acidic detail lifts and extra pressure does not. The supply is genuinely mixed: two rivers, collector wells beside the Missouri, and conventional wells south of the Kansas. Commercially the city runs on the College Boulevard corporate corridor and premium south-side residential, with a storm-driven spike in May and June.
WaterOne publishes its figures in full, so Overland Park's water is among the best-documented on this site. Total hardness averaged 144 mg/L as calcium carbonate in 2024 with a range of 119 to 172, and calcium hardness alone averaged 88 mg/L. At 144 the city sits in the hard band rather than the very-hard one that begins at 181, and the band is what changes the opening line of a quote.
The decisive fact is not the hardness, it is that WaterOne deliberately makes its water scale-forming. The utility states that its chemistry is designed to micro-deposit calcium and magnesium to form a protective barrier between the water and plumbing materials, and it reports a positive saturation index of 0.79 to 1.4. Finished water leaves at pH 9.1 to 9.6, well above the 8.5 secondary standard. Water engineered to deposit minerals inside a pipe will deposit them on glass too, and it will do it as an alkaline film rather than as discrete spots.
That film is why a plain water rinse underperforms here. An alkaline, mineral-depositing supply at pH 9.6 responds to an acidic detail cleaner; adding pressure or volume mostly spreads it. This is the single most useful chemistry fact for an Overland Park route and it comes straight from the operator's own report.
The sourceType on this record is genuinely mixed, and that is worth stating because most of the water data on this site has turned out to be wrong. WaterOne draws from the Kansas and Missouri Rivers, from collector wells adjacent to the Missouri, and from conventional wells south of the Kansas River. In 2024 that was 14.76 billion gallons of Missouri River water, 6.09 billion from the Kansas River, 5.22 billion from the Wolcott collector well and 38 million from the Kansas River wells — 26.28 billion gallons in total. Surface and true groundwater both, so mixed is correct.
Softening is conditional rather than constant. WaterOne adds lime and, depending on the raw water profile at the time, possibly soda ash to counteract calcium and magnesium — which means the degree of softening varies with what the rivers are delivering. That is the mechanism behind the 119 to 172 range, and it is why a single point value describes this supply less well than the band does.
Sulfate averages 169 mg/L against a 250 secondary standard but ranges to 270, and total dissolved solids sit at 353. Odour threshold is reported at 3 T.O.N., exactly at the secondary standard, ranging to 5. Bromate, a by-product of the ozone disinfection stage, averages 3.8 ppb against a 10 ppb limit but ranges to 13.
One utility serves this city and a dozen more, which matters for route economics: WaterOne covers Overland Park, Lenexa, Leawood, Shawnee, Prairie Village, Mission, Merriam, Mission Hills, Roeland Park, Fairway, Westwood, Lake Quivira, Mission Woods and Westwood Hills, plus portions of Olathe, De Soto and Bonner Springs, across roughly 2,800 miles of main. A method that works on Overland Park glass works across most of Johnson County.
Overland Park is the wealthiest market in Kansas, and the premium-residential plus corporate-headquarters commercial book is meaningfully larger than the city's size alone would suggest. Spring storm season concentrates post-event cleaning through May and June, with hail damage to screens a routine secondary call.
Overland Park prices at the top of the Kansas range because the pane counts are high and the stock is premium, not because the work is technically harder. Add for height on south-side elevations, add for screen and frame work under mature canopy and after hail, and expect the corporate corridor to be quoted on contract frequency and access compliance. The shared WaterOne supply means a method proven here transfers across most of Johnson County without rework.
Brookridge and similar mid-century single-storey stock is within a homeowner's reach, with the same caveat that governs the whole city: never let this water air-dry, because at pH 9.6 the film sets harder than ordinary spotting. The large south-side premium elevations are worth hiring out on pane count and height alone. Mission Farms coated glazing is where a wrong chemical choice costs the unit rather than the wash, and College Boulevard curtain wall is contract access work.
OPEN COST ESTIMATOR →2025 annual mean at the Heritage Park monitor, 13899 W 159TH, 7.4 km south-west of the city (EPA site 20-091-0010).
Largest air release: Universal Engraving Inc, 9090 Nieman RD (fabricated metals), inside the city limits, 93 lb in 2024.
Overland Park is served by WaterOne, whose rules reserve public hydrants for fire protection: only district staff may open one, and anyone else needs special permission, an approved backflow device and a district-issued meter billed on a temporary-use account. In a sudden shortage the district board can ban uses by priority, starting with fountains, pools and car washing.
WaterOne (Water District No. 1 of Johnson County) Rules and Regulations, Rule VI and Rule III §4 · checked September 2026
Overland Park's stormwater pollution chapter lists what may never be released into the storm sewer system, and it names wastewater from a commercial mobile power washer or from washing a building exterior whenever that water carries soap, detergent, degreaser, solvent or any surfactant cleaner; anyone who lets a banned material reach the system must contain and clean it up.
Overland Park Municipal Code 7.58.050: specific prohibitions and duties · Overland Park Municipal Code 7.58.070: release reporting and cleanup · checked September 2026
Overland Park's Unified Development Ordinance divides the city into twenty conventional and nineteen planned zoning districts plus a flood hazard area, and none is a historic district; the ordinance sets up no preservation commission and mentions historic structures only in its floodplain rules, so replacing window glass needs no historic approval beyond ordinary permits and design standards.
Overland Park Municipal Code 18.150.010: districts designated · checked September 2026
Springtime atmospheric deposition of nitrogen-based fertilizer and pre-emergence herbicides applied across millions of wheat-belt acres. Produces brown-yellow film on east-facing residential glass. Wet-rinse-first protocol — same handling as the Iowa nitrate-runoff wave but heavier in western Kansas.
Wind-erosion soil deposition during dry stretches produces heavy brown film on east-facing and south-facing residential glass. Dry-brush pre-clear required. The 2011-2014 drought years produced documentation of this pattern at intensities not seen since the 1930s Dust Bowl years.
Wet-only handling. Elm and oak pollen heaviest in Wichita, Topeka, Lawrence, and KC. Western Kansas pollen-load light due to limited deciduous canopy.
Published, current, and unusually complete. WaterOne reports total hardness as calcium carbonate averaging 144 mg/L with a 119 to 172 range for 2024, plus calcium hardness at 88 mg/L, calcium 37 and magnesium 14.
Residential window cleaning in Overland Park typically runs $10–15 per pane or $290–470 for a standard single-story exterior. Overland Park prices at the top of the Kansas range because the pane counts are high and the stock is premium, not because the work is technically harder.
Overland Park's drier, frost-free months are July to September, by NOAA's 1991–2020 normals for the Olathe Johnson County Executive Airport station, where May brings the most rain. The calendar on this page marks July (after the April 16 bloom and after smoke season). Frost nights usually run from October 29 to April 8.
Not as the final rinse: WaterOne publishes hardness of 144 mg/L, enough to spot as it dries, so finish with pure water. Its sodium, up to 62 mg/L, leaves a salt film that pulls moisture back, so rinse it off rather than let it dry. It draws on the Kansas and Missouri Rivers and adjacent collector wells, in the utility's own words.
In Overland Park the dominant residue patterns include alkaline mineral film from water engineered to deposit — ph 9.1 to 9.6, saturation index +0.79 to +1.4 and total hardness 144 mg/l, ranging 119 to 172 as river profiles shift. Mineral film is the year-round constant and is worst in hot, sunny, dry conditions where rinse water flashes off before it can be pulled.
Brookridge and similar mid-century single-storey stock is within a homeowner's reach, with the same caveat that governs the whole city: never let this water air-dry, because at pH 9.6 the film sets harder than ordinary spotting. The large south-side premium elevations are worth hiring out on pane count and height alone.
The original town core around Santa Fe Drive, with the oldest commercial frontage in the city and street-level traffic film over the alkaline supply film. Two deposits, two passes. Leawood-adjacent south OP and Mission Farms have their own housing stock and glazing as well.
Just over the Kansas line