Bromate in Drinking Water: The Public 0.010 mg/L Line

By SubcontractorHub Editorial Team·Published October 2026

Dealers meet bromate in drinking water on a city report, or on a lab sheet next to an ozone conversation. The four-row block that also holds chlorite, haloacetic acids, and trihalomethanes is disinfection byproducts in drinking water. This page is only the bromate row. The national primary rules apply to public water systems. They are not a private-well statute.

Bromate in Drinking Water on the Primary Table

The national primary drinking water regulations are legally enforceable primary standards that apply to public water systems. In the disinfection byproduct block, bromate's MCLG cell is zero. The MCL is 0.010. The potential health effect listed is an increased risk of cancer. The source cell says byproduct of drinking water disinfection.

The table header puts those figures in milligrams per liter unless otherwise noted. The notes say milligrams per liter are equivalent to parts per million. 0.010 mg/L is therefore 0.010 ppm on that note. It is not a different standard. Moving the same digits to micrograms per liter uses the 1,000-to-1 scale on milligrams and micrograms. 0.010 mg/L is 10 µg/L on that scale. Write both labels if the lab used the smaller unit, so a later reader does not think 10 is a new limit.

An MCLG is the level below which there is no known or expected risk to health. It allows a margin of safety and is a non-enforceable public health goal. An MCL is the highest level allowed in drinking water. MCLs are enforceable standards, set as close to the goals as feasible using the best available treatment technology and taking cost into consideration. Zero in the goal cell is not a second MCL sitting under 0.010.

The 0.010 Figure in the 2025 CFR

Section 141.64 of the 2025 Code of Federal Regulations prints the maximum contaminant levels for bromate and chlorite in one short table. Bromate is 0.010 mg/L. Chlorite is 1.0 mg/L. Those are the same public numbers as the national primary table. Do not add them together. The chlorite row has its own page, chlorite in drinking water.

The same paragraph names compliance dates for community water systems and non-transient non-community water systems. Subpart H systems serving 10,000 or more persons were to comply beginning January 1, 2002. Subpart H systems serving fewer than 10,000 persons, and systems using only ground water not under the direct influence of surface water, were to comply beginning January 1, 2004. Those dates are public-system dates. They are not a private-well deadline.

What Is the Bromate Average on a Public System?

Section 141.133 says bromate compliance must be based on a running annual arithmetic average, computed quarterly, of monthly samples. For a month in which the system takes more than one sample, those samples are averaged first. If the average of samples covering any consecutive four-quarter period exceeds the MCL, the system is in violation of the MCL. If a public water system fails to complete 12 consecutive months of monitoring, compliance for the last four-quarter period is based on an average of the available data.

That average is not the locational running annual average used for trihalomethanes and haloacetic acids. The trihalomethane row, including why one sample is not that locational math, is total trihalomethanes in drinking water. A dealer who copies the trihalomethane sentence onto a bromate line has mixed two rules. A single sample from a private tap is not either average.

Ozone Control Is the Listed Technology, Not a Percent

The best available technology named for bromate is control of the ozone treatment process to reduce production of bromate. That sentence is about how a public system runs ozone. It does not state a removal percentage, an empty-bed time, or an installed price. The well-treatment conversation that already warns about bromide and ozone is ozone water treatment. This page does not add a generator size or a dose.

A softener, a sediment cartridge, and a UV lamp are not named in that technology sentence. Do not tell a household that one of those stages “handles bromate” because the word disinfection appeared on the source cell. The source cell is how the byproduct gets into the water story. It is not a parts list.

What to Write on the Ticket

1. The number, the unit the lab printed, and the word bromate. Do not file it under “byproducts.”
2. Whether you set it beside the public 0.010 mg/L line, and whether you also wrote 10 µg/L as the same line.
3. Whether the paper is one sample or a utility average of monthly samples. Do not invent the quarterly average.
4. Whether the address is a public system or a private well. The statute sentence depends on that.
5. No removal percentage and no installed price, unless a separate sourced quote says so.

Where Bromate in Drinking Water Stops

This page does not say when bromate will form, and it does not name a bromide concentration that makes formation certain. It does not convert bromate into a trihalomethane, a haloacetic acid, or chlorite. A private well can still be compared with 0.010 mg/L as a public benchmark. That comparison does not turn the house into a public water system, and it does not create a violation under the sentences above.

A water treatment dealer who writes the row name next to the digits can explain the sheet without borrowing the ozone page's equipment talk. The testing panel for a private well is a different document. Keep this line labeled as the public bromate MCL.

Frequently Asked Questions