Rochester's Hemlock Lake water is moderately hard at 88 to 120 mg/L, oak, birch and maple pollen peak April to May, and winter brings road-salt aerosol.
Rochester's own Hemlock Lake water is moderately hard, while many suburbs drink Lake Ontario water from the county, so check which supply you have before judging a spot. Oak, birch and maple pollen peak in spring and winter brings road-salt spray, which leaves July to September as the dependable window. Ornate original glazing along the East Avenue and Park Avenue corridors calls for conservation methods at higher rates, while a single-story exterior runs $280 to $480.
The city and its suburbs drink different water, which is the first thing to establish before quoting anything. Rochester proper draws Hemlock and Canadice, protected upland Finger Lakes, while the county authority supplies Lake Ontario water to much of the surrounding area. The city's own report gives 88 to 120 mg/L for Hemlock water, which is moderately hard.
Figures by source, as reported.
| Hardness | 88–120 mg/L as CaCO₃ 2025 entry-point averages: 88 mg/L from the Hemlock plant and 120 on the Lake Ontario water bought from MCWA; moderately hard on the USGS ladder, as published by City of Rochester Water Bureau (Hemlock and Canadice Lakes, with Lake Ontario supply via Monroe County Water Authority). |
|---|---|
| pH | 8 (range 7.53–8.53) |
| Alkalinity | 72–92 mg/L as CaCO₃ |
| Sodium | 15–20 mg/L |
| Chloride | 25–39 mg/L |
| Total dissolved solids | 170–200 mg/L |
| Disinfectant | free chlorine |
| Source and treatment | Surface water, per the EPA SDWIS federal record; the city draws on Hemlock and Canadice Lakes with Lake Ontario supply available through the Monroe County Water Authority · Rapid sand filtration with pre and post chlorination and fluoridation · No softening step. |
Not in the report: corrosion index, iron and manganese.
SOURCE · City of Rochester 2025 Water Quality Report (NY2704518), entry-point table for the Hemlock plant and purchased Lake Ontario water, as reprinted by the Village of Lima, with the EPA SDWIS federal treatment record · How we source these numbers
The upstate pollen complex is heavier than a single-species wave because oak, birch and maple overlap through April and May, and the combined load needs a presoak rather than a dry first pass. Winter runs the other clock: lake-effect snow off Ontario brings sustained road treatment, and salt aerosol reloads lower glass through every cycle rather than once a season.
NEW YORK SEASON BY SEASON →Rochester proper draws Hemlock and Canadice, two protected upland Finger Lakes, through the City of Rochester Water Bureau. The Monroe County Water Authority is a separate operator supplying much of the surrounding suburbs with Lake Ontario water, so city and suburb are on different sources and no figure proven on one transfers to the other. The city's 2025 report puts hardness at 88 mg/L from Hemlock and 120 on the Lake Ontario supply. The East Avenue mansion district's Tiffany and leaded glazing is the technical and commercial high point of the market; lake-effect road salt and an overlapping three-species pollen wave set the seasonal intervals.
The City of Rochester runs its own Water Bureau supplied mainly from Hemlock and Canadice Lakes, two protected upland Finger Lakes, while the Monroe County Water Authority supplies much of the surrounding suburbs with Lake Ontario water. City and suburb are on different sources: the city's Hemlock plant averages 88 mg/L of hardness, while the Lake Ontario water bought from the county authority runs 120.
City and county are genuinely different waters, and the distinction is easy to get wrong. A crew moving between city and suburban addresses is moving between an upland lake supply and a Great Lake supply with different mineral profiles, and no figure proven on one transfers to the other.
Figures quoted online for Rochester run as high as 12.5 and 15.2 grains per gallon, from the same site on different pages. A number found online here may be contradicted by the same site elsewhere.
The upstate pollen complex overlaps oak, birch and maple through April and May, and the combined load is heavier than the single-species waves further south. It needs a presoak rinse rather than a dry first pass, because the mixed pollen smears rather than brushing off.
East Avenue carries one of the most ornate concentrations of original residential glazing in the northeast, including Tiffany commissions, leaded panels and bevelled French casements. Those assemblies cannot be replaced, a wet came joint does lasting harm, and the work is conservation contracting priced on time.
Lake-effect winter off Ontario drives sustained road treatment from late autumn into spring, and salt aerosol reloads lower glass with every cycle. Presoak protocols on the bottom third are standard here between November and March, because dragging salt-borne grit across glass scores it.
Heritage concentration supports rates the wider Rochester economy would not. The East Avenue and Park Avenue corridors carry ornate original glazing on properties whose owners expect conservation method and documentation, and that work is priced on time and risk. Against it, the general residential market is price-sensitive and competitive, so the two ends barely overlap.
The East Avenue mansion district is the reason this market has a high skill ceiling. Tiffany commissions, leaded panels and bevelled French casements are common there, and those are irreplaceable assemblies where a wet came joint or a confident blade does damage that cannot be undone. Ordinary residential elsewhere in the city is well within a homeowner's reach.
OPEN COST ESTIMATOR →2025 annual mean at the Rochester 2 monitor, 2 Yarmouth Road, RG&E Substation, 6.2 km south-east of the city (EPA site 36-055-1007).
2025 annual mean at the Rochester Near-Road monitor, I-490 and 1775 East Avenue, Rochester, NY 14610, 5.6 km south-east of the city (EPA site 36-055-0015).
Largest air release: Eastman Kodak Co Eastman Business Park, 1669 Lake AVE (chemicals), inside the city limits, 26,821 lb in 2024.
In a drought or other water shortage, Rochester's commissioner can issue rules restricting consumers' water use, with penalties of up to $500 per violation.
Rochester Code §23-34: water shortage · checked September 2026
Rochester makes it unlawful to discharge sewage or other polluted water to any natural outlet in the city without suitable treatment.
Rochester Code §97-3: discharge of untreated wastes prohibited · checked September 2026
In Rochester's preservation districts, no one may secure or issue a permit for covered work until a certificate of appropriateness has been issued; the Director of Zoning and Permitting can approve certificates for work that follows the preservation guidelines, and the Preservation Board hears the rest.
Rochester Zoning Code §120-194: procedures approved by the Preservation Board · checked September 2026
Heavy road salting from December through March produces an aerosolized salt mist that bonds to ground-floor glass and corrodes aluminum and steel sash hardware over time. The salt film cleans off but the underlying frame damage is cumulative. Worst in NYC, Long Island, and the snow belt.
South Shore exposures see salt aerosol off the Atlantic year-round, with the heaviest deposition during nor'easter season. Combined with the elevated iron content in some Long Island groundwater, this produces an orange-rust tint on hard-water deposits that does not clear with citric acid alone.
The hardwood pollen wave in the Hudson Valley, the Adirondacks, and the western tier runs heavy from mid-April through May. Yellow pollen films horizontal glass and the upper third of vertical glass on east-facing exposures. Requires a surfactant pre-rinse on most spring jobs north of Westchester.
The pre-1945 wood-sash housing stock in NYC, Westchester, and the older upstate cities is reaching the end of its original glazing putty service life. The putty crumbles around the perimeter of the pane and produces a chalky residue on the lower edge of the glass that cleaning does not solve. Documentation and a glazier referral are the right move.
Rochester runs on City of Rochester Water Bureau (Hemlock and Canadice Lakes, with Lake Ontario supply via Monroe County Water Authority) lake or reservoir surface water at a published 88–120 mg/L (CaCO₃) — 2025 entry-point averages: 88 mg/L from the Hemlock plant and 120 on the Lake Ontario water bought from MCWA; moderately hard on the USGS ladder.
Residential window cleaning in Rochester typically runs $9–14 per pane or $280–480 for a standard single-story exterior. Heritage concentration supports rates the wider Rochester economy would not.
Rochester's drier, frost-free months are July to September, by NOAA's 1991–2020 normals for the Rochester Greater International Airport station. The calendar on this page marks July (after the May 10 bloom and after smoke season). Frost nights usually run from October 25 to April 24.
Yes, if the rinse is squeegeed off before it dries: City of Rochester Water Bureau (Hemlock and Canadice Lakes, with Lake Ontario supply via Monroe County Water Authority) publishes dissolved solids of 170–200 mg/L, between this site's two dissolved-solids flags. Treatment starts with rapid sand filtration with pre, post chlorination and fluoridation.
In Rochester the dominant residue patterns include upstate pollen complex of oak, birch and maple, april to may and lake-effect road-salt aerosol on lower panes through winter. The upstate pollen complex is heavier than a single-species wave because oak, birch and maple overlap through April and May, and the combined load needs a presoak rather than a dry first pass.
The East Avenue mansion district is the reason this market has a high skill ceiling. Tiffany commissions, leaded panels and bevelled French casements are common there, and those are irreplaceable assemblies where a wet came joint or a confident blade does damage that cannot be undone. Ordinary residential elsewhere in the city is well within a homeowner's reach.
Pre-1920 commercial core; institutional and converted-loft residential. Park Avenue and East Avenue have their own housing stock and glazing as well.
Just over the New York line