Lewiston shares a very soft lake supply with Auburn, about 17 mg/L, and because it is unfiltered, seasonal lake behavior reaches the tap directly.
Lewiston shares Lake Auburn with its twin city, and the water is soft, about 17 mg/L, so minerals leave little on the glass. Because the supply is unfiltered, the lake's seasons show up at the tap, with autumn turnover adding organic load just as the leaves come down. Height and storm windows, both products of the local housing, drive the price; June, August and September are the months to book, and a single-story exterior runs $220 to $370.
Lewiston drinks Lake Auburn, the same unfiltered lake Auburn drinks, and the districts say so in as many words. The published figure is seventeen milligrams per litre — one grain per gallon, soft. Neither utility softens and neither treatment train touches calcium or magnesium, so what the lake carries is what reaches the tap. Scale is not the Lewiston problem; film and drying speed are.
| Hardness | 17 mg/L as CaCO₃ Soft, as published by the Lewiston Water Division. |
|---|---|
| Iron | 0.012 mg/L |
| Manganese | 0.0019 mg/L |
| Sodium | 16.5 mg/L |
| Chloride | 16 mg/L |
| Disinfectant | chloramine |
| Source and treatment | Lake Auburn, fed by a mostly forested watershed across Buckfield, Turner, Hebron, Minot and East Auburn, and protected by the Lake Auburn Watershed Protection Commission formed jointly by the two utilities · UNFILTERED, which is rare: the EPA has exempted both the Auburn Water District and the Lewiston Water Division from the requirement to filter before disinfection, on the strength of the lake's quality. Water enters through an intake pipe, passes a coarse screen and drum strainer, then ultraviolet light treatment to inactivate viruses. Chlorine is added for disinfection, alkalinity is increased, pH is adjusted, fluoride is added, a corrosion inhibitor is dosed, and the chlorine is then converted to chloramines with ammonia sulfate for the distribution residual. · No softening step. |
Not in the report: pH, alkalinity, corrosion index and total dissolved solids.
SOURCE · Auburn Water & Sewerage Districts, 2023 Consumer Confidence Report, 'Secondary Contaminants (Aesthetic Standards)' table and the Description of Water Treatment Process (awsd.org). Lake Auburn has been the source of Lewiston and Auburn's public drinking water since 1875 and the report covers both. The Lewiston Water Division's own report publishes no hardness row, so the shared-source document is the operator record for this city. · How we source these numbers
Two heavy seasons at opposite ends of the year. November to April is road treatment, and the salt-and-sand film climbs higher on street-facing glass than customers expect — which makes the first wash after the treatment season the year's most valuable and its busiest. October brings the hardwood drop and the lake's turnover together, filling tracks and putting organic load through an unfiltered supply at the same time. Between them, high summer is the comfortable window and the one where a wash holds longest.
MAINE SEASON BY SEASON →Lewiston is a mill city drinking an unfiltered lake it shares with Auburn, and the Auburn Water & Sewerage Districts publish that lake water at about 17 mg/L — very soft — which is the figure used here. What the arrangement does produce is a supply unusually exposed to its own source: with no filter bed between Lake Auburn and the tap, the lake's autumn turnover reaches the glass more directly than it would anywhere with a conventional plant, and it coincides with the hardwood leaf drop. The dominant facts here, though, are built rather than chemical. This is dense nineteenth-century brick and the New England triple-decker, three storeys of flats on narrow lots, which makes ladder work the norm and storm windows a routine doubling of labour per opening. Over a hundred freeze-thaw crossings a year lift putty out of pre-1900 sash, so much of the honest work is frame attention. And the spring salt-removal wash, after five months of road treatment, is the most valuable job of the Lewiston year.
Lewiston and Auburn drink the same lake and have done since 1875, which makes this the clearest regional-provider case in Maine even though the two cities run separate utilities. The figure used here comes from the Auburn Water & Sewerage Districts, which draw the same lake and publish about 17 mg/L — very soft. A separate Lewiston figure, if one exists, would describe essentially the same raw water.
Lake Auburn is clean enough that the EPA excuses both cities from filtering it at all, which is rare and consequential. An unfiltered surface supply means there is no filter bed between the lake and the tap, so what the lake does in a given season reaches the glass more directly than it would in a conventional plant city.
That waiver is conditional on the watershed staying undeveloped, and the condition is live rather than theoretical — it has been the subject of dispute between the two cities. If it is ever lost, both build filtration plants, and the character of the finished water changes for the first time in a century and a half.
The lake's own calendar is therefore the supply's calendar. Autumn turnover mixes the water column and puts organic load into the raw supply at the same time the hardwood leaf drop lands on the glass — two unrelated seasonal events that peak together and make late autumn the least rewarding time to wash here.
Lewiston is a Franco-American mill city and the built environment is the operational headline. The Bates Mill complex and the canal system that powered it define the downtown, and the surrounding stock is dense nineteenth-century brick — tenement blocks, multi-light sash, painted-in glazing lines and a great deal of original glass still in service.
The characteristic housing type here is the New England triple-decker, three storeys of wood-frame flats at high density. That geometry is the single biggest pricing factor in the city: three floors of windows on a narrow lot with limited setback means ladder work on almost every job and no easy pole angle on the upper flats.
Storm windows are still in service across much of the older stock, often wooden and often painted in. They double the labour per opening and they are where the real risk of damage lies — a blade that would be safe on modern glazing takes paint and putty off a hundred-year-old sash.
Maine winters put down heavy road salt and sand from November into April, and the valley streets hold the resulting film high on street-facing elevations. The spring wash is a salt-removal job and it needs a flood rinse rather than a wipe; it is also the year's peak demand, which prices accordingly.
Freeze-thaw here runs well over a hundred crossings a year and is the process that actually destroys glazing in this city. On pre-1900 sash it lifts putty and opens joints, which is why so much of the honest work in Lewiston is frame and sash attention rather than cleaning.
Height and storm windows dominate Lewiston pricing, and both are functions of the housing type rather than of difficulty. A triple-decker is three elevations of ladder work; storm windows double the openings. The spring salt wash is peak demand and books out, so late requests into that window carry a premium. Bates College and the Lisbon Street frontage carry the route density that keeps residential rates reasonable, and anything on the river frontage at the falls needs a shorter interval than the streets behind it.
Triple-deckers are the answer here. Three storeys of flats on a narrow lot with minimal setback means there is no safe pole angle to the top floor and no comfortable ladder position either, and this is the most common housing type in the city rather than an exception. The second reason is the glass itself: pre-1900 sash with painted-in glazing lines and wooden storm windows still fitted does not tolerate a blade, and a homeowner clearing a winter salt film with anything acidic risks the putty as much as the glass.
OPEN COST ESTIMATOR →2025 annual mean at the Country Kitchen Bakery Parking LOT monitor, Lewiston Country Kitchen Bakery Lot & Canal ST, 3.4 km west of the city (EPA site 23-001-0011).
Largest air release: Dingley Press, 119 Lisbon ST (printing), 1.8 km outside the city limits, 7,789 lb in 2024.
Lewiston's fire code says only someone with authority may take the cap off a city hydrant, and no one may meddle with a hydrant, block its approach or reduce its readiness for an emergency, so a washing crew cannot simply open one to fill its tank without that authorization.
Lewiston Code Ch. 38 Sec. 38-2: unauthorized use of hydrants prohibited · checked September 2026
Under Article VI of Lewiston's utilities chapter, nobody may start or keep up a non-storm water discharge into the city storm drains, even through a connection the city once allowed; street wash water is allowed only where no detergents are used and spilled material is gone, and the car-washing exemption covers individual residents, not commercial crews.
Lewiston Code Ch. 74 Sec. 74-205: prohibition of non-storm water discharges · checked September 2026
Lewiston's zoning code requires a certificate of appropriateness from its Historic Preservation Review Board, or staff for minor items, before any change to exterior window sash, windows or other exterior features of a designated historic building or a contributing building in a listed historic district; the board judges the type and style of windows against its review criteria.
Lewiston Zoning and Land Use Code Art. XV Sec. 5: certificates of appropriateness · checked September 2026
Extended citric pre-treatment (3-5 minutes) plus citric-rinse finish required on the properties that leave the heaviest scale. Verify chemistry on individual properties.
Lewiston runs on the Lewiston Water Division lake or reservoir surface water at a published 17 mg/L (CaCO₃) — soft. Lewiston drinks Lake Auburn, the same unfiltered lake Auburn drinks, and the districts say so in as many words. The published figure is seventeen milligrams per litre — one grain per gallon, soft.
Residential window cleaning in Lewiston typically runs $7–12 per pane or $220–370 for a standard single-story exterior. Height and storm windows dominate Lewiston pricing, and both are functions of the housing type rather than of difficulty.
Lewiston's drier, frost-free months are June and August and September, by NOAA's 1991–2020 normals for the Lewiston station. The calendar on this page marks June (after the May 20 bloom and after smoke season). Frost nights usually run from October 19 to April 25.
Usually yes: the Lewiston Water Division publishes hardness of 17 mg/L, low enough that tap-rinsed glass tends to dry clean. Treatment starts with uNFILTERED, which is rare: the EPA has exempted both the Auburn Water District, the Lewiston Water Division from the requirement to filter before disinfection and on the strength of the lake's quality.
In Lewiston the dominant residue patterns include very soft shared lake supply — about 17 mg/l, from the auburn side's own published figure and unfiltered surface supply, so seasonal lake behaviour reaches the tap directly. Two heavy seasons at opposite ends of the year.
Triple-deckers are the answer here. Three storeys of flats on a narrow lot with minimal setback means there is no safe pole angle to the top floor and no comfortable ladder position either, and this is the most common housing type in the city rather than an exception.
Nineteenth-century mill and commercial buildings on the canal system, with large-format industrial glazing in the mill blocks and original sash in the commercial frontage. Two different trades inside a few streets. The Tree Streets and Bates College and the surrounding streets have their own housing stock and glazing as well.
Just over the Maine line