Haloacetic Acids in Drinking Water: The Public 0.060 mg/L Line

By SubcontractorHub Editorial Team·Published October 2026

Haloacetic acids in drinking water are easy to mix up with the trihalomethane sum, because both are disinfection byproducts and both use a group MCL. They are not the same row. The map of the block is disinfection byproducts in drinking water. The neighboring sum, at 0.080 mg/L, is total trihalomethanes in drinking water. This page stays on HAA5.

Haloacetic Acids in Drinking Water Use 0.060 mg/L

On the disinfection byproducts table, haloacetic acids (HAA5) have an MCLG cell of n/a and an MCL of 0.060. Units are milligrams per liter unless the table says otherwise. The health-effects cell says increased risk of cancer. The source cell says byproduct of drinking water disinfection. That is the whole row this page is allowed to treat as the public group line.

The national primary drinking water regulations say these primary rules apply to public water systems. A private well is not that system. You can still show the customer the public number as a benchmark you fetched. You cannot tell them the well “failed the MCL” because a single jug printed a digit above 0.060.

Five Acids, and Two of Them Have No MCLG

Footnote 6 says there is no collective MCLG for the group, then it names individual goals for some of the acids. It also says bromoacetic acid and dibromoacetic acid are regulated with this group but have no MCLGs. Leaving those two off the note, because the goal cell is empty, drops part of the group the rule actually names.

A lab may print HAA5 as one total, or it may print the acids on separate lines. Keep the label the PDF used. Adding a trihalomethane into this total, because both are “byproducts,” makes a number the method did not report.

Do Not Add HAA5 to the Trihalomethane Line

0.060 and 0.080 are different cells. A customer who sees both on a city report is looking at two compliance checks, not one blended score. Write each total next to its own name. If only one total is on the sheet, do not estimate the other.

Bromate at 0.010 mg/L and chlorite at 1.0 mg/L are the other two rows in the same public block. They are not HAA5. The hub page holds those two figures so this article does not turn into a second copy of the whole table. Chlorine and chloramine residuals are a different table again. Read them on chloramine in drinking water.

The Public Average Is an LRAA, Not Your Sample Bottle

40 CFR Part 141 Subpart V covers locational running annual averages for both TTHM and HAA5. Quarterly public monitoring builds an LRAA at each monitoring location, and that LRAA is what is compared with the MCL. More than one sample in a quarter at the same location is averaged first. Yearly or less frequent monitoring treats each sample as having to be under the MCL, and if none exceeds it, that sample is considered the LRAA for that location.

A dealer holding one private-well PDF has not performed that calculation. Say “one sample, dated, at this tap.” If the customer is a public-water user and hands you a consumer report, copy the utility's own average and the year it names. Do not recompute it from memory.

60 µg/L Is the Same Mass as 0.060 mg/L

When the sheet uses micrograms, use the thousand-to-one scale on milligrams and micrograms. 0.060 times 1,000 is 60. The public MCL does not become 60 mg/L because the unit changed, and it does not become a new goal. Parts per million, per the EPA unit note, match milligrams per liter digit for digit. 0.060 mg/L and 0.060 ppm are that pair.

Keep both labels if you convert, the way the milligrams page already asks. A note that keeps only 60, with no unit, will not match the PDF on the next visit.

What to Put on the Job Ticket

The laboratory, the date, the address or sample point, HAA5 or the individual acid names that were actually printed, the unit, and a word for what the number is: one sample, or the utility average you copied. If bromoacetic acid or dibromoacetic acid is missing, write missing. Do not fill the cell with zero.

Planning a private-well panel is the well water testing guide. This page does not add HAA5 as a federal requirement for that well. Primary versus secondary standards, so a customer can see that this MCL is in the enforceable public set, are in primary and secondary drinking water standards.

What Stays Off the Quote

No removal percentage for carbon, reverse osmosis, or any other device. No contact time. No claim that a softener addresses this row. No installed price. The fetched table names the contaminant, the public figures, the health-effects phrase, and the source phrase. It does not name a home treatment in that cell, so this page does not invent one.

A water treatment dealer who saves the five names and the unit can explain the sheet later. A dealer who writes “byproducts, needs carbon” cannot show which acid was on the PDF.

Do Not Borrow a Goal to Fill a Blank

The footnote prints MCLGs for three acids and says two acids in the group have none. An empty MCLG is not a result. A missing lab cell is not an MCLG. If the sheet leaves bromoacetic acid or dibromoacetic acid blank, write blank.

Do not copy “zero” from dichloroacetic acid onto a different line. Zero on that one goal is the footnote's figure for that acid. It is not a measurement, and it is not a value you may lend to an acid the footnote left without a goal.

The 0.060 Line Is Not a Sum You Build at the Table

HAA5 on the public table is the group's MCL. It is not an instruction to add five household tests by hand and call the addition the public compliance figure. If the laboratory already reported a group result, copy that result and the unit.

If it reported acids one by one, copy them one by one. Do not invent the group total from a partial list. A sheet that names three acids has three acids on it. The public 0.060 mg/L figure stays the table's MCL, not a number you completed in the truck.

Keep This Row Off the Trihalomethane Total

A sheet can show both groups. They stay on separate lines. Adding 0.060 to 0.080 does not create a combined public limit, and a high result on one row does not move the other row's MCL.

The trihalomethane page holds the 0.080 figure and the four names in that footnote. This page does not repeat those four names. Send the reader there when the sheet's other total is the question, and keep HAA5 labeled HAA5 on this note.

Say What the Fetch Did Not Include

No removal percentage. No claim that a softener, a carbon bed, or a reverse-osmosis unit hits a stated percent on this group. No installed price. The job ticket can still list the five names the lab printed, the unit, the sample date, and whether the figure is one sample or a utility average.

How Should a Dealer Read Haloacetic Acids in Drinking Water?

Read 0.060 mg/L as the public group MCL, then read the footnote before you assume every acid has a goal. Keep HAA5 separate from the 0.080 mg/L trihalomethane line. Say whether the paper in your hand is one sample or a locational running annual average. Leave any removal sentence off the proposal until you have a source that states it.

Frequently Asked Questions