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— FLORIDA WATER REPORTS • READER GUIDE

How to read a Florida water quality report without getting misled

A utility report is the right place to start—but the year, units, sampling locations and comparison columns determine what its numbers actually mean.

Read these four things first
  1. Confirm the report belongs to the utility printed on your bill.
  2. Check the report year and the date each contaminant was actually sampled.
  3. Compare the reported result with the correct enforceable limit—not an unrelated health goal or private benchmark.
  4. Read the footnotes before deciding what a highest level, range or “not detected” result means.

What is a Consumer Confidence Report?

EPA requires community water systems to provide customers with a Consumer Confidence Report, often called an annual drinking-water quality report. Reports are due each year by July 1 and summarize the previous calendar year's water source, regulated detections, violations and other required information.

A current report can contain an older sampling result because some contaminants are monitored less often than once a year. The cover year tells you when the report was issued; the table's sample date tells you when that particular water was tested.

Step 1: make sure it is your utility

Florida city names, mailing addresses and ZIP codes do not reliably identify a water provider. A home inside one city can receive water from a county, a neighboring municipality, an independent district or a private system.

Start with the utility name on the water bill. If water is included in rent or association fees, ask the property manager which public water system serves the property. Reading a nearby utility's report can give you accurate numbers for the wrong water.

Step 2: understand the comparison columns

MCL

The Maximum Contaminant Level is an enforceable limit for a regulated contaminant. EPA sets it as close to the health goal as feasible while considering available measurement and treatment technology and cost.

MCLG

The Maximum Contaminant Level Goal is a non-enforceable public-health goal with a margin of safety. A result above the goal is not automatically a violation; compare compliance with the MCL or other applicable rule.

MRDL and MRDLG

These are the enforceable maximum residual disinfectant level and its non-enforceable goal. Chlorine and chloramine are added intentionally to control microbes.

Action level or treatment technique

Some rules do not use a simple system-wide maximum. Lead and copper results, for example, can trigger corrosion-control, replacement, notice or other required actions.

Step 3: read the result—not just the contaminant name

Finding a contaminant name in a table does not mean the utility violated a rule. Reports often list regulated substances that were detected below the enforceable limit, along with substances that were tested but not detected.

A column labeled “highest level detected” is not necessarily the amount found throughout the system or at your home. A range shows variation among samples or locations. The report's compliance value may be an annual average, a locational running annual average, a percentile or another calculation required by the specific rule.

Do not compare unlike numbers.

A one-time highest result, a system-wide average, an MCLG, an enforceable MCL and a private organization's benchmark answer different questions. A dramatic comparison is meaningless unless the units, period and regulatory measure match.

Step 4: check the units

Small unit labels can change a result by a thousand times. Milligrams per liter are generally equivalent to parts per million; micrograms per liter are parts per billion; and nanograms per liter are parts per trillion.

For example, 0.004 milligrams per liter equals 4 micrograms per liter—not 0.004 parts per billion. Never copy a number into a different unit without converting it.

What does “not detected” mean?

“Not detected,” “ND” or a less-than symbol usually means the laboratory did not detect the substance at or above the method's reporting or detection level. It should not automatically be translated as absolute zero.

Look for a reporting limit, detection limit or table note. Different laboratories and methods can have different capabilities, so two “ND” results are not necessarily identical measurements.

What does a violation mean?

A violation is not merely a detection. The report should identify the rule that was violated, the period involved, potential health effects, what happened and what the system did or is doing to correct it.

Some violations concern a contaminant limit; others concern monitoring, reporting, treatment or public-notification requirements. That distinction matters. A missed monitoring requirement is serious because required evidence is absent, but it is not proof that the contaminant exceeded its limit.

What the annual report cannot tell you

When should you consider testing at the home?

Home-specific testing is appropriate when the question involves lead or copper from plumbing, a private well, a localized color or odor problem, a vulnerable household member, or the performance of installed treatment. Use the right sample method and a Florida-certified laboratory when the concern is health-specific.

Basic hardness, pH and total-dissolved-solids screening can help explain scale or treatment conditions. Those measurements do not identify lead, PFAS, bacteria, pesticides or other specific contaminants.

A reliable five-minute review

  1. Match the utility to the bill.
  2. Find the source water and treatment summary.
  3. Scan for violations and required public notices.
  4. For each concern, record the sample date, reported result, units and applicable limit.
  5. Decide whether your question is system-wide or specific to the property.

The bottom line

A Florida water-quality report is valuable evidence, but it has boundaries. It describes a regulated public water system over a reporting period. Read the correct utility, sample date, units, result type and enforceable comparison before drawing a conclusion—and use property-level testing for a property-level question.

Understand what “safe,” detected and compliant mean →

See what a home water screening can—and cannot—show →

Learn how heavy rain, PFAS and tap water differ →

Check current verified Florida water alerts →

Find your utility and official water report →

Article status

Published September 14, 2026 · No corrections posted.

This guide explains annual public-water reports. It does not replace a current utility notice or property-specific laboratory test.

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