City of Largo Water Quality Report

DID YOU KNOW water quality reports, also known as “Consumer Confidence Reports (CCRs),” are annual documents that all public water systems are required to provide to you via mail and online. These reports are supposed to provide important information about the quality of the drinking water delivered over the previous year.

They can be difficult to read or understand. They are often many pages long and contain complex tables and charts. Culligan Water wants to change this and help you MAKE SENSE OF YOUR WATER.

This easy-to-read report will provide you with the following:

1) Infrastructure Improvements

Largo’s water treatment system uses advanced processes like aeration, lime softening, and chloramine disinfection to maintain high water quality. Sodium hydroxide is added to stabilize pH and reduce pipe corrosion. Continuous monitoring and testing ensure that all water delivered to homes complies with state and federal safety standards. The Cosme Water Treatment Plant, together with Tampa Bay Water’s facilities, plays a key role in delivering reliable service to Largo residents.

2) Water Sources and Usage

Largo receives its drinking water from Tampa Bay Water (TBW), which supplies a mix of groundwater, surface water, and desalinated seawater.

This blended portfolio ensures a consistent, safe water supply for Largo.

3) Disinfection Byproducts

The 2024 report shows the presence of disinfection byproducts, which form when disinfectants react with organic matter in the water. Reported averages include:

All values remained well within EPA’s maximum allowable limits.

4) Minerals and Water Quality Highlights

Largo’s water is classified as moderately hard, with an average hardness of about 165 mg/L. Key mineral findings include:

Additional tests for metals like arsenic (0.4 ppb), barium (0.0148 ppm), and chromium (3.2 ppb) all came back well below EPA maximum contaminant levels (MCLs).

5) Lead and Copper Results

Sampling in 2023 showed that lead and copper levels in Largo’s tap water did not exceed federal action levels:

Both results indicate that Largo’s water remains in compliance, though the presence of these metals is generally linked to household plumbing rather than the water supply itself.

6) Radioactive and Other Contaminants

Tests also detected naturally occurring radioactive materials at very low levels:

All were reported well within federal limits.

In 2024, Largo’s water quality report recorded an average water hardness of 210 mg/L (about 12.3 grains per gallon), which classifies the supply as hard water. While this isn’t among the highest levels in Florida, it is enough to cause everyday issues like scale buildup on faucets and shower doors, mineral deposits in plumbing and appliances, and dry skin or hair. Because Largo’s hardness levels remain consistent from year to year, many homeowners choose to install a water softener or whole-house filtration system to reduce buildup, extend appliance life, and improve comfort at home.

Radioactive contaminants like radium and uranium can enter water sources naturally through soil and rock deposits. Largo’s 2024 water quality report detected very low levels of these substances — well below EPA maximum limits, but still worth monitoring.

Common contaminants can come from natural sources, industrial discharges, agricultural runoff, or corrosion of plumbing systems. Largo’s 2024 report detected the following:

Disinfection byproducts (DBPs) are formed when disinfectants like chlorine or chloramines react with natural organic matter in the water. Common DBPs include trihalomethanes (TTHMs) and haloacetic acids (HAA5s). Florida does not set its own goals for these contaminants, but the EPA has enforceable limits. Largo’s 2024 water quality report showed the following results, all within EPA standards:

For reference, a part per trillion (ppt) is roughly equivalent to a single drop of water in 20 Olympic-sized swimming pools or one second in 32,000 years. These updated interim Health Advisory Levels are below the detection capabilities of current laboratory testing technology. They serve as interim guidance until formal regulations or Maximum Contaminant Levels are established.

PFAS (per- and polyfluoroalkyl substances), commonly known as ‘Forever Chemicals,’ water contamination impacts residents in many places across the United States. However, Largo’s 2024 water quality report does not list PFAS levels, saying “PFAS compounds were not detected in any of the drinking water samples collected at the entry point into our distribution system.”

PFAS contamination is a growing concern across Florida. Installing a reverse osmosis filter is one of the most effective ways to reduce PFAS if present. Florida’s most recent legislation against PFAS requires the Florida Department of Environmental Protection (DEP) to establish specific cleanup levels for PFAS in drinking water, groundwater, and soil by 2025.

On April 10, 2024, the United States government introduced its first-ever national, legally enforceable drinking water standard to protect citizens from PFAS forever chemicals. While this is a major development in the regulation of PFAS, there are over 12,000 types of PFAS, and only six types are being regulated by the EPA.