Cary water is soft at 25 to 30 mg/L, pine and oak pollen hit in March and April, and each March the town switches from chloramine to free chlorine.
Cary's water is soft and the town tells customers not to soften it, so a plain tap rinse finishes clean; pine and oak pollen in early spring are the main mess, and each March the town switches its disinfectant from chloramine to free chlorine. Late spring and early autumn, April, May, September and October, are the best times to wash. Uniform master-planned streets let a crew fit more jobs into a day, and a single-story exterior runs $280 to $480.
At 25 to 30 ppm the supply contributes essentially nothing to what ends up on the glass, and the town says as much by telling customers not to soften it. Tap rinsing finishes clean on ordinary residential work, and the deionised upsell has no argument here that would survive a look at the published figure.
| Hardness | 25–30 mg/L as CaCO₃ The town's own words are 'very soft', and it states that water softeners are not recommended for its customers, as published by Town of Cary Public Works. |
|---|---|
| pH | 8 (range 7.46–8.74) |
| Alkalinity | 33 mg/L as CaCO₃ (range 25–42) |
| Iron | not detected |
| Manganese | 0–0.01 mg/L |
| Sodium | 26 mg/L |
| Chloride | 16 mg/L |
| Total dissolved solids | 109 mg/L (range 96–132) |
| Disinfectant | both (seasonal switch) |
| Source and treatment | B. Everett Jordan Reservoir (Jordan Lake), Cape Fear River basin, treated at the Cary/Apex Water Treatment Facility six miles from the lake and shared with the Town of Apex · Super-Pulsator flocculator clarifiers, sixteen conventional and biological multi-media filters, ozone for disinfection, organics removal and taste-and-odour control, then ammonia and chlorine for the final residual except each March when ammonia is suspended, and fluoride at 0.7 ppm · No softening step. |
Not in the report: corrosion index.
SOURCE · Town of Cary 2025 Water Quality Testing Summary for the Cary/Apex Water Treatment Facility, Water Quality Characteristics tables, with the EPA SDWIS federal treatment record · How we source these numbers
Cary's interval is set almost entirely by the pollen calendar, with one wrinkle no other city on this site has: the disinfectant switch to free chlorine lands in the same March-to-April weeks. The practical pattern is to wait out the wave, reset hard in late April, then run a light cycle through the summer that varies with canopy rather than with anything in the water.
NORTH CAROLINA SEASON BY SEASON →Cary publishes its finished hardness at 25 to 30 ppm and calls it very soft in its own words, adding that softeners are not recommended for its customers. The record carried 110, four times that and two bands out. The town also publishes a full brewer-facing chemistry table and switches disinfectant from chloramine to free chlorine every March — an annual, scheduled change in the water itself. Above that, Cary is the most uniform housing stock in the Triangle and the easiest route economics on this site.
The town answers the hardness question directly on its own public-works FAQ: finished water runs 25 to 30 ppm, which it describes as very soft, and it states plainly that water softeners are not recommended for its customers. A utility actively telling customers not to treat their water is the strongest possible signal that mineral handling is not the job here.
Cary publishes a What's On Tap chemistry table aimed at brewers and other technical users — alkalinity 33 ppm ranging 25 to 42, calcium 8.49, magnesium 2.32, sodium 26, sulfate 33. That is the third utility on this site to publish its water chemistry for a trade rather than for regulators, after Raleigh's Home Brewer's Corner and Columbia's non-regulated parameters table, and those pages are consistently the most precise source available for a city.
Cary switches disinfectant seasonally, running chloramine from mid-April through February and free chlorine through March and into mid-April. The town publishes both residuals, averaging 2.96 ppm on chloramine and 2.19 on free chlorine. It is a scheduled annual change in the water arriving at a tap, and it lands in the same weeks as the pollen wave.
Water comes from Jordan Lake through the Cary/Apex Water Treatment Facility, jointly operated with the Town of Apex and also serving Morrisville and the Wake County part of Research Triangle Park. Cary additionally sells finished water to Durham in shortfall years, so this one plant reaches well beyond the town line.
Jordan Lake is designated nutrient-sensitive water, and it very nearly dried up in the 2006 to 2008 drought. Both facts matter to this trade: the first drives seasonal taste-and-odour treatment, and the second is why drought-year restrictions on non-essential outdoor water use are a live risk to the exterior season here.
Cary's inventory is dominated by master-planned subdivisions built to consistent specification, which is unusual and commercially significant. Uniform glazing, predictable pane counts and short drives between jobs make route economics better here than anywhere else in the Triangle, and per-job pricing genuinely can be standardised.
The pine and oak pollen wave through March and April is the heaviest loading event of the year and arrives in the same weeks as the chlorine switch. It is coarse and it returns within days during the peak, so the useful residential reset comes after it clears rather than during it.
The tech corridor — the campuses in and around Cary plus Research Triangle Park overflow — supplies a steady commercial book on quarterly contracts. It is low-rise, modern, curtain-wall and podium glazing rather than high-rise, which keeps the work accessible but puts it on formal procurement.
Route density is the driver that makes Cary work commercially: uniform master-planned stock and short drives mean a well-built round carries more jobs per day than anywhere nearby, and pricing can genuinely be standardised by house type. Against that, the older enclaves under canopy take longer than their size suggests, and the tech-corridor book prices at bid on quarterly cycles rather than at the door.
This is the most homeowner-friendly water and the most homeowner-friendly glazing in the Triangle, and saying otherwise would not survive the town's own FAQ. The honest professional case here is not chemistry, it is height, frequency and time — two-storey fixed units over landscaping, and the recurring schedule that keeps a house ahead of the pollen rather than chasing it.
OPEN COST ESTIMATOR →2025 annual mean at the Millbrook School monitor, 3801 Spring Forest RD., 24 km east of the city (EPA site 37-183-0014).
2025 annual mean at the Triple Oak monitor, 2826 Triple OAK Drive, 9.3 km north of the city (EPA site 37-183-0021).
Largest air release: Kellanova - Cary Bakery, ONE Quality LN (food), inside the city limits, 127,418 lb in 2024.
Cary's year-round water waste ordinance (Sec. 36-83) forbids spraying streets, driveways or other paved areas so heavily that water flows into storm drains, overwatering until it runs off into the street or down parking lots, and leaving known leaks, breaks or malfunctions unrepaired beyond a reasonable time.
Town of Cary: Water Waste Ordinance (Sec. 36-83) · checked September 2026
Cary's town code bars anyone from throwing, draining or discharging pollutants or polluted water into its storm sewer system, directly or through people under their control. The exempt flows include lawn watering and street wash water but not a contractor's detergent rinse.
Cary Code 14.3.7: illegal discharges to the town storm sewer · checked September 2026
After a Cary landmark or historic district is designated, no exterior part of a building there may be altered or restored until the Historic Preservation Commission approves a certificate of appropriateness, and it must be issued before any building permit. A certificate is required even for work that needs no permit at all.
Cary Code 3.27.2: certificates of appropriateness · checked September 2026
The Triangle and eastern Piedmont parent rock weathers to a more iron-bearing clay than the Atlanta Piedmont. Lower-sash splatter on intown stock needs oxalic rather than citric to lift cleanly. A citric-only protocol leaves a faint orange ghost stain.
Loblolly and shortleaf pine pollen blankets south-facing exposures for two to three weeks each spring. Same handling as Atlanta: wet only, never scrape, light alkaline wash to lift the film.
At 25 to 30 ppm the supply contributes essentially nothing to what ends up on the glass, and the town says as much by telling customers not to soften it. Tap rinsing finishes clean on ordinary residential work, and the deionised upsell has no argument here that would survive a look at the published figure.
Residential window cleaning in Cary typically runs $9–14 per pane or $280–480 for a standard single-story exterior. Route density is the driver that makes Cary work commercially: uniform master-planned stock and short drives mean a well-built round carries more jobs per day than anywhere nearby, and pricing can genuinely be standardised by house type.
Cary's drier, frost-free months are April and May and September and October, by NOAA's 1991–2020 normals for the Raleigh Durham International Airport station, where July brings the most rain. The calendar on this page marks April (after the March 27 bloom), September (after smoke season) and October (before frost). Frost nights usually run from November 4 to March 31.
Yes, if the rinse is squeegeed off before it dries: Town of Cary Public Works publishes dissolved solids of 109 mg/L, between this site's two dissolved-solids flags. It draws on B. Everett Jordan Reservoir (Jordan Lake), Cape Fear River basin, treated at the Cary/Apex Water Treatment Facility six miles.
In Cary the dominant residue patterns include pine and oak pollen wave (march–april) and seasonal disinfectant switch from chloramine to free chlorine each march. Cary's interval is set almost entirely by the pollen calendar, with one wrinkle no other city on this site has: the disinfectant switch to free chlorine lands in the same March-to-April weeks.
This is the most homeowner-friendly water and the most homeowner-friendly glazing in the Triangle, and saying otherwise would not survive the town's own FAQ. The honest professional case here is not chemistry, it is height, frequency and time — two-storey fixed units over landscaping, and the recurring schedule that keeps a house ahead of the pollen rather than chasing it.
Revitalised pre-1920 commercial core with substantial storefront glass at street level. The only genuinely old glazing in the town and the only work here needing heritage judgement. Heritage Pines and Preston have their own housing stock and glazing as well.
Just over the North Carolina line