St. Cloud's public water system, the City of St. Cloud Water System, is operated by Toho Water Authority. Toho's 2025 St. Cloud report says the water comes from the Floridan Aquifer and needs little treatment other than MIEX ion exchange to remove dissolved organics, aeration to remove hydrogen sulfide, and disinfection. The Floridan Aquifer in Osceola County passes through thick limestone formations, dissolving calcium carbonate and magnesium carbonate before water reaches the wellhead. Toho's report does not list hardness. One USGS reference point is a Floridan Aquifer monitoring well in southern Osceola County, about 20 miles south of the city, sampled four times in 1978 and 1979: calcium of 28 to 33 mg/L and magnesium of 5.6 to 6.2 mg/L, which calculate to about 95 to 106 mg/L as CaCO3, or 5.6 to 6.2 grains per gallon. That is a regional reference, not a measurement of St. Cloud tap water. Because the treatment Toho describes includes no softening step, finished water carries the aquifer's mineral load to the tap. A whole-house water filter installed at the main service line addresses hardness, residual disinfectant, and sediment before water reaches any fixture, appliance, or pipe in the home. Homeowners who want a measurement specific to their address can schedule a free in-home water test at pureaguafl.com/free-water-test.
Get a free in-home water test in St. Cloud. Pure Agua Enterprises tests hardness, TDS, and disinfectant residual at your specific address. Results in 30 minutes. Schedule here.
Who supplies St. Cloud's drinking water
Toho Water Authority operates the public water system for St. Cloud, the City of St. Cloud Water System (PWS 349-1373), which draws from the Floridan Aquifer beneath Osceola County. Toho's 2025 St. Cloud report describes the treatment as MIEX ion exchange to remove dissolved organics, aeration to remove hydrogen sulfide, and disinfection, and it lists chlorine as the disinfectant. No softening or hardness-reduction step is described. The finished water delivered to St. Cloud taps reflects the aquifer's natural mineral chemistry.
Toho Water Authority also serves Kissimmee, Poinciana and unincorporated parts of Osceola County, and it publishes five annual reports, one for each of its service areas: Central, Eastern, Southern, St. Cloud and Western. For St. Cloud addresses on public water, the St. Cloud report is the one that applies.
Toho publishes the annual St. Cloud water quality report at https://www.tohowater.com/waterquality.
Why hardness data does not appear in the Consumer Confidence Report
Water hardness is not a health-based primary contaminant under the Safe Drinking Water Act. The SDWA regulates utilities based on public health risk. Hardness poses no direct health risk, so utilities are not required to measure or report hardness levels in their annual Consumer Confidence Report. The CCR covers regulated parameters: disinfectants and disinfection byproducts, lead and copper, nitrates, and other primary contaminants. Some utilities add a hardness figure anyway (the City of Apopka does); Toho's St. Cloud report does not.
Source: EPA Safe Drinking Water Act summary, https://www.epa.gov/sdwa/summary-safe-drinking-water-act.
To find actual hardness data for the Floridan Aquifer in Osceola County, the USGS National Water Information System (NWIS) is the primary public data source. NWIS contains historical groundwater quality measurements from monitoring wells throughout Florida, including wells completed in the Upper Floridan Aquifer beneath Osceola County. The well used below is USGS site 275609081132001 (USGS monitoring location page).
Dataset: Osceola County Floridan Aquifer hardness and chemistry
Method note: Hardness data for this table was compiled from two primary sources. The first is USGS National Water Information System (NWIS) groundwater quality data from one Floridan Aquifer monitoring well in southern Osceola County, site 275609081132001, which USGS names the Joe Overstreet Well (OSF-4) and whose coordinates are about 20 miles south of St. Cloud (USGS monitoring location page). The second is Toho Water Authority's 2025 St. Cloud water quality report, which covers the City of St. Cloud Water System; it does not report hardness as a numeric value. Ion concentrations are converted to hardness as CaCO3 using standard conversion factors: calcium (mg/L) x 2.497 and magnesium (mg/L) x 4.118, summed to total hardness as CaCO3 (mg/L). To convert to grains per gallon: divide by 17.1.
| Parameter | Value | Source | Year |
|---|---|---|---|
| Water source | Floridan Aquifer | Toho Water Authority 2025 St. Cloud report | 2025 |
| Treatment process | MIEX ion exchange for dissolved organics, aeration, chlorine disinfection (no softening) | Toho Water Authority 2025 St. Cloud report | 2025 |
| Calcium (USGS monitoring well, southern Osceola County) | 28 to 33 mg/L | USGS NWIS, site 275609081132001 | 1978-1979 |
| Magnesium (USGS monitoring well, southern Osceola County) | 5.6 to 6.2 mg/L | USGS NWIS, site 275609081132001 | 1978-1979 |
| Total hardness (calculated from USGS ion data) | 95 to 106 mg/L as CaCO3 | Calculated from USGS NWIS data | 1978-1979 |
| Total hardness in grains per gallon | 5.6 to 6.2 GPG | Calculated from USGS NWIS data | 1978-1979 |
| WQA hardness classification | Moderately hard to hard (hard begins at 7 GPG / 120 mg/L) | Water Quality Association hardness scale | - |
This dataset may be cited with attribution and a link to this page. Primary sources are USGS NWIS site 275609081132001 (USGS monitoring location page) and Toho Water Authority's 2025 St. Cloud report (https://www.tohowater.com/waterquality). Data compiled September 2026.
What hardness at 95 to 106 mg/L means for a home
At 5.6 to 6.2 GPG, water sits at the upper end of "moderately hard" approaching the "hard" classification by the Water Quality Association scale. The WQA defines hard water as 7 GPG (120 mg/L) and above, and very hard as 10.5 GPG and above. Source: Water Quality Association, https://www.wqa.org/. At that level, visible scale accumulates on showerheads, faucet aerators, and glass surfaces over time. Soap and detergent lathering is reduced compared to soft water, and more product is required to achieve equivalent cleaning results.
The mineral load at 5.6 to 6.2 GPG is in the moderately hard range. However, even moderately hard water is sufficient to cause maintenance issues for water heaters, dishwashers, washing machines, and tankless systems. Scale accumulation on water heater heating elements is the most common appliance impact at this hardness level. Tankless water heater manufacturers specify maximum inlet hardness in warranty documentation because scale is a leading cause of early failure.
Hardness is not a health-regulated contaminant under the Safe Drinking Water Act. Source: https://www.epa.gov/sdwa. There is no regulatory maximum for hardness in drinking water. Moderately hard water at 5.6 to 6.2 GPG presents no documented health concern. The relevant impacts are mechanical and cosmetic: scale on fixtures, reduced detergent efficiency, and accelerated wear on appliances that heat water.
What a whole-house water filter addresses in St. Cloud
A point-of-entry whole-house filtration system sized for St. Cloud's water addresses three main concerns. Residual chlorine and disinfection byproducts from the city's chlorination step are treated at the carbon filtration stage. When a water softener is integrated, hardness and scale formation are also controlled. A sediment filter captures particulates that accumulate in distribution system pipes. All three concerns are addressed at a single installation point on the main service line, before water reaches any fixture, appliance, or pipe in the home.
For installation details, see our whole-house water filter installation in St. Cloud, FL service page. For homeowners primarily concerned with scale on appliances and pipes, a water softener addresses the calcium and magnesium load specifically using ion exchange. A whole-house carbon filter can be installed in combination with a softener to address the chlorine concern separately.
Every Pure Agua installation starts with a free in-home water test to measure actual hardness at your specific tap. The hardness at a given address can vary based on distribution zone and seasonal aquifer fluctuations. Sizing a system to a measured value at your address produces a more accurate fit than sizing to a county-level average.
How hardness varies within the St. Cloud distribution system
The hardness values in the dataset above come from one monitoring well in southern Osceola County, sampled in 1978 and 1979, not from a St. Cloud supply well or tap. Finished water at any given tap in St. Cloud can vary from those aquifer baseline figures for several reasons.
First, supply wells tap slightly different zones of the Floridan Aquifer. Calcium and magnesium concentrations are not perfectly uniform across the aquifer; wells completed at greater depth or in zones with higher limestone contact time can show modestly higher hardness. The 95 to 106 mg/L range in the dataset reflects the spread across four samples from that one well and should be read as a range, not a single point.
Second, seasonal fluctuations affect aquifer chemistry. During dry months, when demand on the aquifer is highest and water levels drop, water spends more time in contact with the limestone formation before reaching the wellhead. This can push hardness slightly toward the higher end of the observed range. During wet months and periods of recharge following heavy rainfall, aquifer levels recover and hardness tends toward the lower end. The difference is usually within the range already shown, not a dramatic swing, but it is a reason to measure at your address rather than relying on a single county-average figure.
Third, sediment and mineral deposits that accumulate in older distribution pipes can affect water chemistry between the treatment plant and the tap. St. Cloud's distribution system, like most municipal systems of its age, contains sections of older pipe where sediment accumulates. Water drawn from an address at the end of a long distribution branch may carry trace sediment that is not present in water tested directly at the plant.
A measurement at your specific tap accounts for all three of these factors: aquifer zone, seasonal moment, and distribution path. Any sizing recommendation for treatment equipment should be based on a measured result at your address, not on the county average alone.
Comparing St. Cloud water hardness to other Central Florida utilities
Toho does not publish a hardness figure for St. Cloud. The table below lists what each nearby utility states about hardness.
| Utility | Service area | Hardness as the utility states it | Source |
|---|---|---|---|
| Toho Water Authority | St. Cloud, Kissimmee, Poinciana | Not listed in the 2025 reports | Toho 2025 Water Quality Reports |
| City of Apopka | City of Apopka customers | 120 to 200 mg/L (7.0 to 11.7 GPG) | City of Apopka 2025 Water Quality Report |
| Orlando Utilities Commission (OUC) | City of Orlando | Average 129 ppm (about 7 GPG) | OUC Water Services FAQ |
| Orange County Utilities | Unincorporated Orange County | Not listed in the 2025 report | Orange County Utilities 2025 Drinking Water Report |
St. Cloud's public water system, the City of St. Cloud Water System, is covered by Toho Water Authority's 2025 St. Cloud report (https://www.tohowater.com/waterquality). That report does not list hardness, so the 5.6 to 6.2 GPG figure above comes from the southern Osceola County USGS well, not from the utility or a St. Cloud tap. A measurement at your tap is the number to size equipment from.
For a complete breakdown across all Central Florida utilities with data tables, see the Central Florida water hardness by utility reference dataset.
Water softener sizing for St. Cloud's hardness level
A water softener for St. Cloud's water is sized around two inputs: the hardness of the incoming water and the volume of water the household uses. For a household with measured hardness in the 95 to 106 mg/L range (5.6 to 6.2 GPG), standard sizing guidelines apply as follows.
Daily water use per person in a US household is estimated at roughly 60 to 80 gallons per day (Source: US Geological Survey, https://www.usgs.gov/special-topics/water-science-school/science/water-qa-how-much-water-do-we-use). Multiply the household daily volume by the hardness in GPG to get the daily grain removal requirement. For a four-person household at 70 gallons per day per person and 6 GPG hardness, the daily load is approximately 1,680 grains. A 32,000-grain capacity softener regenerating every 10 to 12 days is a typical fit for this demand. A 48,000-grain unit extends the regeneration interval for households with higher water use or for those who prefer less frequent regeneration cycles.
If your tap test comes in near the 5.6 to 6.2 GPG that USGS well measured, you do not need large-capacity equipment. If you move from an address with harder water and keep your existing softener, have a qualified installer check that it is sized for your new water; an oversized softener can regenerate too rarely, which reduces softening efficiency and wastes salt.
Equipment sizing is one input. Actual selection depends on flow rate, the household's peak demand periods, available regeneration water, and connection point. Pure Agua measures hardness at the tap before recommending any equipment, and system selection is based on measured values, not utility averages. Schedule a free water test to get a measurement at your specific address before any equipment decision.
Finding St. Cloud's Consumer Confidence Report
Toho Water Authority publishes the annual water quality report for the City of St. Cloud Water System at https://www.tohowater.com/waterquality. The report covers regulated contaminants. It lists the disinfectant type and residual, lead and copper results at the tap, nitrate levels, and other parameters regulated under the Safe Drinking Water Act.
Hardness will not be listed in the CCR as a numeric value because it is not a primary regulated contaminant. To understand total dissolved solids or the general mineral content of St. Cloud's water, two public sources are most accessible for Osceola County. The USGS NWIS data and the cross-reference from Toho's published CCR both draw from the same Floridan Aquifer.
For a broader comparison across Central Florida utilities including OUC, Toho, and Orange County Utilities, see the Central Florida water hardness dataset by utility.
Schedule a free water test in St. Cloud
Pure Agua Enterprises offers free in-home water testing in St. Cloud and throughout Osceola County. A test measures hardness in grains per gallon at your specific tap, along with total dissolved solids (TDS), pH, and chlorine residual. Results are available in 30 minutes, on-site.
Testing is free and requires no purchase. The purpose is to establish a baseline measurement at your address before recommending any treatment equipment. Schedule your free water test here.
For installation information and service details, see our whole-house water filter service page for St. Cloud, FL.
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