Beryllium in Well Water: The Public 0.004 mg/L Line

By SubcontractorHub Editorial Team·Published October 2026

A metals panel can list antimony, beryllium, and cadmium on one page. The digit next to beryllium is not the digit next to antimony, and it is not the digit next to cadmium. Dealers who sell treatment still have to say which public line they are reading. SubcontractorHub is software for the customer record. This page is the row. It is not a treatment design.

The Public 0.004 mg/L Line for Beryllium in Well Water

The national primary drinking water regulations are legally enforceable primary standards and treatment techniques that apply to public water systems. In the inorganic block, beryllium shows an MCLG of 0.004 and an MCL of 0.004. The potential health effects cell says intestinal lesions. The source cell says discharge from metal refineries and coal-burning factories, and discharge from electrical, aerospace, and defense industries.

Footnote 2 says units are in milligrams per liter unless otherwise noted, and that milligrams per liter are equivalent to parts per million. 0.004 mg/L is therefore 0.004 ppm on that note. It is not a second standard hiding under a different name. Moving the same digits to micrograms per liter uses the 1,000-to-1 scale on milligrams and micrograms. 0.004 mg/L is 4 µg/L on that scale. Write both labels if the lab used the smaller unit, so a later reader does not think 4 is a new limit.

An MCLG is a goal. An MCL is the enforceable public number. On this row the two cells print the same digit. That match is not true of every neighbor. The definitions of those two words are on MCL and MCLG. A goal is not a fine, and a matching pair is still one line.

The 0.004 mg/L Figure in the Inorganic Table

Section 141.62, as printed on the Cornell eCFR page fetched the same day, lists maximum contaminant levels for inorganic contaminants. Beryllium is item (12), at 0.004 mg/L. Antimony, the item before it, is 0.006 mg/L. Cadmium, earlier on that table, is 0.005 mg/L. Those are not one number. The antimony row has its own page, antimony in well water. The cadmium row has its own page, cadmium in well water.

Paragraph (b) says the levels in items (11) through (16), which include beryllium, apply to community and non-transient, non-community water systems. A private well is not named in that sentence. A dealer who copies the 0.004 mg/L line onto a kitchen-tap jug still has to say the jug is not the public-system rule. The difference between a city system and a private well is what is a public water system.

Beryllium in Well Water Is Not the 0.006 mg/L Row

Antimony prints 0.006 mg/L on the same national table, with a health cell about blood cholesterol and blood sugar and a source cell that names petroleum refineries, fire retardants, ceramics, electronics, and solder. That is a different metal and a different source sentence. Mercury (inorganic) prints 0.002 mg/L, on mercury in well water. Selenium prints 0.05 mg/L, on selenium in well water. Do not paste a solder sentence onto the beryllium row because both names sat on one lab PDF.

The source sentence you are allowed to repeat from this fetch is metal refineries, coal-burning factories, and electrical, aerospace, and defense industries. If the lab header says beryllium, that is the source cell. Adding the neighbors together is not the rule this page fetched.

What the Note Holds, and What It Does Not

The table above is the note. It is not a quote, and it is not a removal design. A customer who wants a price still needs a test, a model, and a scope. Those live on the job. This page only stops the wrong digit from landing in the scope.

What the BAT Marks Do Not Promise

The BAT table on the same Cornell page marks beryllium as 1, 2, 5, 6, and 7. The key says 1 is activated alumina, 2 is coagulation and filtration, 5 is ion exchange, 6 is lime softening, and 7 is reverse osmosis. The key also says coagulation and filtration, and lime softening, are not BAT for systems with fewer than 500 service connections. Those marks identify a technology the rule names for compliance with the MCL. They do not say what percent a cartridge in a basement will remove.

A city plant and a point-of-entry tank are not the same machine. If you sell ion exchange, say you sell ion exchange. Do not say the number 5 is a guarantee on this well. No removal percentage was fetched for this row, so none is printed here. Antimony, on the same technology table, is marked only 2 and 7. That shorter list is another reason not to copy one metal's marks onto the other.

What Should the Beryllium in Well Water Note Say?

Five lines keep the next visit from borrowing a neighbor. Name the metal the lab printed, show the unit before anyone compares it with 0.004, and say whether the jug is a private well. If a line does not apply, mark it skipped. A blank line looks the same as a step you forgot, and a skipped line is still a line someone can read later.

1. The metal name as the lab printed it, beryllium, not a panel total.
2. The result and the unit. If the unit is µg/L, show the mg/L equivalent on the 1,000 scale before anyone compares it with 0.004.
3. The public pair you compared it with: MCLG 0.004 mg/L and MCL 0.004 mg/L, named as the national beryllium row.
4. Whether the sample is a private well or a public system. Paragraph (b) names community and non-transient, non-community systems for this item.
5. What you did not claim: no removal percent, no installed price, and no statement that 0.004 mg/L is antimony's 0.006 mg/L.

Where the Row Sits on the Job

The lab sheet belongs with the customer, the address, and the date of the sample. A price for equipment is a later page, after someone has read this row and the rows next to it. Mixing the 0.004 mg/L line into a softener quote because the panel listed several metals skips the chemical name.

How a dealer reads a full panel, including which tests were actually run, is the well water testing guide. The software that holds the customer file is water treatment contractor software. This article does not size a filter and does not tell a household the water is safe to drink.

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