Ethylbenzene in Well Water: The Public 0.7 mg/L Line

By SubcontractorHub Editorial Team·Published October 2026

The number 0.7 appears more than once on the national organic table. Ethylbenzene uses it. Glyphosate uses it. They are not the same row, and a dealer who memorizes the digit without the name will quote the wrong source. SubcontractorHub is software for the customer record. This page is the ethylbenzene row. It is not a treatment design.

The Public 0.7 mg/L Line for Ethylbenzene 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 organic block, ethylbenzene shows an MCLG of 0.7 and an MCL of 0.7. The potential health effects cell says liver or kidneys problems. The source cell says discharge from petroleum refineries.

Footnote 2 says units are in milligrams per liter unless otherwise noted, and that milligrams per liter are equivalent to parts per million. 0.7 mg/L is therefore 0.7 ppm on that note. Moving the same digits to micrograms per liter uses the 1,000-to-1 scale on milligrams and micrograms. 0.7 mg/L is 700 µg/L on that scale. A lab that prints 700 is not reporting a new limit. Write both labels so nobody treats 700 as seven hundred times the standard.

An MCLG is a goal. An MCL is the enforceable public number. On this row the two cells print the same digit. The definitions of those two words are on MCL and MCLG. Matching cells are still one chemical, not a license to reuse 0.7 on the next name down the page.

The 0.7 mg/L Figure in the 2025 CFR

Section 141.61 of the 2025 Code of Federal Regulations, in the XML dated 2025-07-01, prints ethylbenzene, CAS 100-41-4, at 0.7 mg/L. Xylenes (total), CAS 1330-20-7, are 10 mg/L on that same table. The xylenes page is xylenes in well water. Toluene is 1 mg/L, on toluene in well water.

Paragraph (a) says those volatile-organic levels apply to community and non-transient, non-community water systems. A private well is not named in that sentence. Copying 0.7 mg/L onto a kitchen-tap jug still requires a sentence that the jug is not the public-system rule. That distinction is what is a public water system.

Ethylbenzene in Well Water Is Not Glyphosate

The national table also prints glyphosate at an MCLG of 0.7 and an MCL of 0.7. The health cell on that row says kidney problems and reproductive difficulties. The source cell says runoff from herbicide use. A shared digit is not a shared chemical. If the lab header says ethylbenzene, the source sentence you are allowed to repeat from this fetch is petroleum refineries, not herbicide runoff.

Benzene at 0.005 mg/L is benzene in well water. Carbon tetrachloride at 0.005 mg/L is carbon tetrachloride in well water. Do not shrink 0.7 to 0.005 because both names sat on a volatile panel. Do not stretch 0.7 up to the xylenes total because both names are associated with petroleum.

A dealer comparing neighboring organics should keep the refinery sentence attached to this chemical and the factory sentence attached to the other names. The 2025 table marks granular activated carbon and packed tower aeration for ethylbenzene, and it leaves the oxidation column empty. Those marks say which treatment techniques the regulation lists. They do not say how much of the chemical a particular unit will remove, and they do not name a price for the equipment. The customer file should store the laboratory result, the unit, and a pointer to this row. Treatment selection stays with the person who designs the system.

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 filter design. Refineries in the source cell describe where the rule says the contaminant can come from. They do not prove that a refinery is upgradient of this well.

Refineries, Not Petroleum Factories

Toluene's source cell, on the same national page, says discharge from petroleum factories. The xylenes source cell says petroleum factories and chemical factories. Ethylbenzene's source cell says petroleum refineries. Those three sentences were fetched as written. Substituting “factory” for “refinery” because it sounds shorter changes the cell.

If a customer asks where it comes from, read the cell you actually compared. If you do not know the local source, say you do not know. The national source cell is not a map of their street.

What the BAT Marks Do Not Promise

Table 2 marks granular activated carbon and packed tower aeration for ethylbenzene. The oxidation column is empty. Those marks identify a technology the rule names for compliance with the MCL. They do not state a percent, an empty-bed time, or a cartridge life.

Selling carbon is a scope you write on the proposal. Pointing at the X in the GAC column and calling it proof is not. No removal percentage was fetched for this row, so none is printed here.

What Should the Ethylbenzene in Well Water Note Say?

Five lines keep 0.7 attached to the right name. If a line does not apply, mark it skipped.

1. The chemical name as the lab printed it, plus CAS 100-41-4 if the sheet has a CAS column.
2. The result and the unit. If the unit is µg/L, show 700 as the µg/L form of 0.7 mg/L before anyone compares the raw number with 0.7.
3. The public pair: MCLG 0.7 mg/L and MCL 0.7 mg/L, named as the national ethylbenzene row, not the glyphosate row.
4. Whether the sample is a private well or a public system. Paragraph (a) names community and non-transient, non-community systems.
5. What you did not claim: no removal percent, no installed price, and no statement that 0.7 mg/L is the xylenes total.

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 comes after someone has read this row and the rows beside it. A petroleum smell is not, by itself, an ethylbenzene result.

How a dealer reads a full panel 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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