Dover runs on groundwater from its own water department, and the glass takes the Atlantic seaboard pollen wave in spring and snow and ice damage in winter.
Dover's water department runs several small plants on separate wells and describes the result as moderately hard to hard without printing a number, so dry glass promptly rather than trusting the rinse. Downtown's mill blocks crowd the Cocheco River with no setback or level ground for staging, and the houses on the hill add a third storey, which is where a Dover quote climbs above the $240 to $400 of a single-story exterior. Book July to September.
The Dover Water Department calls its water inherently hard because it comes from wells: most of its treatment plants deliver moderately hard water, and Pudding Hill's is hard. It publishes those words rather than a measured figure. In practice most of Dover sees a light mineral film while glass on the Pudding Hill supply spots noticeably faster.
Figures by source, as reported.
| Hardness | no figure Dover Water Department publishes only as moderately hard to hard, with no number. |
|---|---|
| pH | 7.25–7.79 |
| Iron | 0.061–0.146 mg/L |
| Manganese | 0.019–0.2163 mg/L |
| Sodium | 26.9–114 mg/L |
| Chloride | 22–190 mg/L |
| Disinfectant | free chlorine |
| Source and treatment | Groundwater, per the EPA SDWIS federal record · Permanganate, greensand filtration and sequestration for iron and manganese, diffused aeration, granular activated carbon, peroxide and ultraviolet radiation, pre and post chlorination, with orthophosphate and polyphosphate inhibitors and post pH adjustment · No softening step. |
Not in the report: alkalinity, corrosion index and total dissolved solids.
SOURCE · Dover Water Department 2025 Consumer Confidence Report (Reporting Year 2024), PWS 0651010, secondary substances table by treatment plant and well · How we source these numbers
Timing the wash after the Seacoast pollen drop ends in June, rather than during it, is what makes it hold here.
NEW HAMPSHIRE SEASON BY SEASON →The supply here is a well field rather than a reservoir, and it is not uniform across the city — the department runs several small treatment plants on separate sources and bands them differently in its own reporting. Downtown is a 19th-century mill district folded into a bend of the Cocheco River, and that history sets most of the glazing a cleaner meets at street level.
Every drop in Dover comes out of the ground. The Dover Water Department draws from the Pudding Hill, Ireland, Hughes, Smith and Cummings wells plus the Calderwood and Campbell supplies, and its consumer confidence report states the cause of the mineral load plainly: the water is hard because the source is wells.
Hardness is not one number here. The department describes most of its treatment plants as delivering moderately hard water and the Pudding Hill supply as hard, without a measured figure for either, so the same wash can dry clean on one street and leave a faint mineral film several blocks away.
At this mineral load evaporation does the damage, not dirt. Rinse water left standing on a sunlit south or west elevation drops its calcium as a haze that a second wash will not lift, so panes in Dover are worked and squeegeed dry in one pass instead of being flooded and left to sheet off.
Winter on the Seacoast is a freeze-thaw machine rather than a deep freeze. Coastal storm tracks push January days above freezing and back below it overnight, and meltwater carrying road salt and grit off the Spaulding Turnpike corridor refreezes on the glass it has just run across.
The spring load is tree pollen rather than dust. Oak, birch, maple and pine drop a yellow-green film across the Seacoast from late April into June, and it binds readily to glass still carrying winter salt. The wash that holds is the one scheduled after the drop finishes, not during it.
Downtown is a pre-1900 mill district and the glass shows it. Sash in the Cocheco mill blocks and the brick storefronts around them is old, thin and often still bedded in original putty, which rules out a razor, rules out soaking the glazing line, and turns a routine storefront into slower hand work.
The newer stock out from the centre carries the opposite risk: post-2010 houses run low-E coated units in sealed frames, where ammonia and acidic scale removers are the quickest way to ruin a window. Two Dover houses a mile apart can need two different chemicals on the same afternoon.
Price here tracks access and storey count more than pane count. The mill-block storefronts are ground-floor, quick and repeatable, which is what supports a recurring downtown book, while the older hill housing adds a third storey and a grade that rarely gives a ladder level footing.
In Dover the quote moves on staging room and storey count — mill-block frontage has neither setback nor level ground, while the hill housing adds a third storey.
The pre-1900 putty-glazed sash downtown and the coated units in the newer subdivisions both punish a generic approach, which is where a Dover professional earns the fee.
OPEN COST ESTIMATOR →2025 annual mean at the Portsmouth - Peirce Island monitor, Portsmouth, Peirce Island, 16.5 km south-east of the city (EPA site 33-015-0014).
Largest air release: Brox Industries Inc, 253 Rochester Neck RD (petroleum), 0.2 km outside the city limits, 0.006 lb in 2024.
Under drought conditions Dover limits residential lawn watering in three levels, which the City Council sets on the recommendation of the Dover Utilities Commission or city staff and announces by public notice.
Dover Code §121-57: restrictions under drought conditions · checked September 2026
Dover's streets ordinance makes it an offence to let liquid from private property, roof and foundation drains included, run onto a public road, sidewalk or city property in a way that creates a hazard for pedestrians or obstructs traffic, so rinse water sheeting across a downtown sidewalk from a wash job falls under it.
Dover Code §125-16(C): snow, ice and liquids on streets and sidewalks · checked September 2026
Dover's zoning ordinance has no local historic district and no certificate-of-appropriateness review for existing buildings. The only historic language sits in the Central Business District rules, which ask new development to respect downtown's traditional character (window proportions, storefronts) through architectural standards an applicant may use; repairing glass on an existing building triggers none of it.
Dover Zoning §170-20: Central Business District regulations · checked September 2026
Late-winter and early-spring ice-melt residue carries chloride-residue, mineral residue, and organic residue composite. Ice-dam meltwater residue from roof-edge ice damming produces a distinctive composite residue on upper-pane and sash-perimeter glass. Percarbonate-citric ladder protocol required on the worst-affected stock.
Dover runs on Dover Water Department groundwater at a hardness Dover Water Department publishes only as moderately hard to hard. The Dover Water Department calls its water inherently hard because it comes from wells: most of its treatment plants deliver moderately hard water, and Pudding Hill's is hard. It publishes those words rather than a measured figure.
Residential window cleaning in Dover typically runs $8–13 per pane or $240–400 for a standard single-story exterior. In Dover the quote moves on staging room and storey count — mill-block frontage has neither setback nor level ground, while the hill housing adds a third storey.
Dover's drier, frost-free months are July to September, by NOAA's 1991–2020 normals for a station near Durham, where June brings the most rain. The calendar on this page marks July (after the May 14 bloom and after smoke season). Frost nights usually run from October 10 to May 3.
Dover Water Department publishes neither hardness nor dissolved solids, so rinse one pane and let it dry in sun; a white ring means switch to pure water. Its manganese, up to 0.2163 mg/L, is at the staining level, and acid cleaners will not lift that film. Treatment starts with permanganate, greensand filtration, sequestration for iron and manganese.
In Dover the dominant residue patterns include atlantic seaboard pollen wave and snow and ice damage. Timing the wash after the Seacoast pollen drop ends in June, rather than during it, is what makes it hold here.
The pre-1900 putty-glazed sash downtown and the coated units in the newer subdivisions both punish a generic approach, which is where a Dover professional earns the fee.
Just over the New Hampshire line