Idaho Falls water is very hard at 240 mg/L, and High Plains wind and agricultural drift keep laying a fresh coat of dust across the glass.
Idaho Falls pumps straight from one of the largest aquifers in the country, and the water is very hard, about 240 mg/L or 14 grains per gallon, so any rinse left to dry on glass leaves scale. High Plains wind and farm drift keep laying fresh dust, and the summer is short: July and August are the dependable months. Older sash near the river and coated glass in the eastern subdivisions need different methods, and a single-story exterior runs $220 to $370.
The city gives its water as 14 grains per gallon, about 240 mg/L, meaning rinse water left on glass in high-desert sun leaves a haze a second wash will not lift.
| Hardness | 240 mg/L as CaCO₃ 14 grains per gallon, in the city's own units, as published by Idaho Falls Water. |
|---|---|
| Disinfectant | free chlorine |
| Source and treatment | Groundwater from the Eastern Snake River Plain aquifer · Post-chlorination; SDWIS records no filtration, softening or other treatment process for the system · No softening step. |
Not in the report: pH, alkalinity, corrosion index, iron, manganese, sodium, chloride and total dissolved solids.
SOURCE · City of Idaho Falls Water Quality Report (2019 Water Quality Data), with the EPA SDWIS federal treatment record, PWS ID7100039 · How we source these numbers
Here the wash has to beat evaporation, so it is scheduled by time of day as much as by season.
IDAHO SEASON BY SEASON →Idaho Falls sits on top of one of the largest aquifers in the United States and pumps straight out of it. The water arrives clean enough to need very little treatment and hard enough — about 240 mg/L, 14 grains per gallon in the city's own words — to punish anyone who lets it dry on glass. That combination, plus a high-desert climate and a national laboratory for an employer, is the whole job here.
The supply is groundwater from wells into the Eastern Snake River Plain Aquifer, which lies in fractured basalt beneath the plain. It comes up cold, consistent and requiring minimal treatment — there is no filtration plant and no seasonal raw-water variation to manage.
The city gives its water's hardness as 14 grains per gallon, about 240 mg/L — very hard. That is the working number here: rinse water left on glass in high-desert sun will leave a visible calcium haze within a single afternoon, and a second wash with the same water will not remove it.
The practical response in this market is either deionised or reverse-osmosis rinse water for final passes, or a strict no-air-dry discipline. Cleaners who move here from a soft-water region get caught by this in their first summer.
Basalt is why the aquifer is so productive and also why the local dust is what it is — fine, dark, volcanic-derived grit that shows against light frames and scratches if it is dragged rather than flooded off.
The Snake River drops through the middle of the city over the falls the place is named for, and the spray and humidity immediately around them are a genuinely different microclimate from the rest of the high desert — the only place in town where glass stays damp.
Idaho National Laboratory is the region's anchor employer, and the office and institutional buildings that come with it are the backbone of the commercial book, with security-controlled access and procurement cycles rather than walk-up calls.
The climate is cold high desert: long freezing winters that close exterior residential work, then a bone-dry summer where the constraint is evaporation speed rather than temperature.
Older housing near the river and downtown runs to pre-1940 stock with original double-hung sash and storm windows, while the growth on the Ammon side is modern coated glazing — two different chemical regimes within a few miles.
Idaho Falls splits on age — pre-1940 sash by the river against coated subdivision glazing east of it — and the quote follows which.
At this hardness a final pass needs deionised or reverse-osmosis water, which is equipment rather than technique.
OPEN COST ESTIMATOR →Nearest EPA particle monitor: 66 km
Largest air release: Frazier Industrial Co, 2255 W 49TH S (furniture), inside the city limits, 20,229 lb in 2024.
Idaho Falls outlaws wasting city water through improper use and bans open-hose irrigation outright; drawing water from a public hydrant takes written permission from the public works, police or fire director, and the water division picks the hydrant and bills for the water. The mayor can also limit water use by proclamation during a shortage.
Idaho Falls City Code 8-4-8 and 8-4-9: waste prohibited; mayor may limit use of water · Idaho Falls City Code 8-4-34: fire hydrants · checked September 2026
Idaho Falls reserves its storm drains for storm water, defined as runoff from rain or snowmelt; unpolluted process water may go in only with the City's approval, and its code separately bars depositing waste or other matter on any street, alley or right-of-way. Soapy water from a window job is neither, so keep it out of the gutter and off the street.
Idaho Falls City Code 8-1-8: unpolluted water discharged to storm drain and storm water definition · Idaho Falls City Code 6-1-2: dumping refuse unlawful · checked September 2026
Idaho Falls has a Historic Preservation Commission, but its role in the city code is to survey, advise and recommend; the comprehensive zoning title, rewritten in 2026, sets up only planned transition, wireless tower and airport overlays and no historic district, so window replacement on older buildings needs no preservation approval.
Idaho Falls City Code 2-11-3 and 2-11-4: Historic Preservation Commission purpose and duties · Idaho Falls Title 11 Comprehensive Zoning, Chapter 5: overlay zones · checked September 2026
High-elevation UV exposure accelerates IGU seal degradation visibly on Sun Valley, Ketchum, McCall, and surrounding Mountain West corridor residential. Document seal-degradation indicators on each residential visit and provide written notation to customer. Same handling framework applies to Park City and Deer Valley.
Treasure Valley and Magic Valley irrigated-agriculture corridor produces a distinctive composite residue on agricultural-services commercial — agricultural dust, irrigation-mineral residue, and standard commercial residue composite. Extended alkaline-soap dwell plus citric-rinse on facility-adjacent commercial.
The city gives its water as 14 grains per gallon, about 240 mg/L, meaning rinse water left on glass in high-desert sun leaves a haze a second wash will not lift.
Residential window cleaning in Idaho Falls typically runs $7–12 per pane or $220–370 for a standard single-story exterior. Idaho Falls splits on age — pre-1940 sash by the river against coated subdivision glazing east of it — and the quote follows which.
Idaho Falls's drier, frost-free months are July and August, by NOAA's 1991–2020 normals for the Idaho Falls Fanning Field station, where May brings the most rain. The calendar on this page marks July (after the May 18 bloom and after smoke season and before frost). Frost nights usually run from September 20 to May 23.
Not as the final rinse: Idaho Falls Water publishes hardness of 240 mg/L, enough to spot as it dries, so finish with pure water. Water left to dry leaves mineral scale; fresh spots lift with a mild acid. It draws on groundwater from the Eastern Snake River Plain aquifer.
In Idaho Falls the dominant residue patterns include high plains wind-driven dust and agricultural drift. Here the wash has to beat evaporation, so it is scheduled by time of day as much as by season.
At this hardness a final pass needs deionised or reverse-osmosis water, which is equipment rather than technique.
Older commercial along the river above the falls: brick blocks, transom glass, original upper sash, and the one part of the city with persistent ambient humidity off the water. Idaho Falls West Side and River Walk have their own housing stock and glazing as well.
Just over the Idaho line