What Is Best Available Technology in Drinking Water?

By SubcontractorHub Editorial Team·Published October 2026

A proposal can name a tank and still have said nothing about which column the rule marked. The dealer still has to read the row. SubcontractorHub is software for the customer record. This page is the phrase. It is not a treatment design, and it is not a price.

A required process that stands in place of an MCL number is what a treatment technique is. The simazine row, carbon only, is simazine in well water. Best available technology is the label on the columns, not a second copy of either page.

Where the Words Best Available Technology Appear

EPA's national primary page, fetched the day this page was written, defines a maximum contaminant level as the highest level of a contaminant that is allowed in drinking water. The same footnote says MCLs are set as close to the MCLGs as feasible using the best available treatment technology and taking cost into consideration, and that MCLs are enforceable standards. That is the sentence. It does not name a brand, and it does not print a percent removed.

The same footnote defines a treatment technique as a required process intended to reduce the level of a contaminant in drinking water. That definition is a different line. When the national table prints TT, the rule is requiring a process instead of publishing a numeric MCL. When the table prints a number, the best-available phrase is about how close that number sits to the goal. Do not swap the two labels because both mention treatment.

Cornell's copy of 40 CFR 141.61(b) then identifies granular activated carbon, packed tower aeration, or oxidation as the best technology, treatment technique, or other means available for achieving compliance with the MCL for the organic contaminants in paragraphs (a) and (c), except PFAS. The columns on table 2 are those three names. An empty cell is part of the row. Filling it because a neighbor was marked is how a note becomes a different chemical.

What Best Available Technology Looks Like on a Row

Simazine is marked only under carbon. 1,2-Dichloroethane is marked under carbon and aeration, with oxidation empty. Vinyl chloride is marked only under aeration. Those three patterns are why a single sentence such as “carbon is the answer” cannot cover the organic table. The row decides. The phrase does not.

The Glyphosate Rows Do Not Agree on Paper

The MCL list in paragraph (c) prints glyphosate at 0.7 mg/L with CAS 1071-53-6. The technology table prints the spelling Gylphosate, CAS 1071-83-6, and marks oxidation only. Carbon and aeration are empty on that technology row. This page fetched both lines on the same day from the same Cornell section. It does not decide which CAS a laboratory should have printed, and it does not correct the spelling.

If the lab header uses one of those two numbers, write that number and say which table you compared it with. If the header uses neither, do not pick the closer one. The national table's glyphosate health cell, kidney problems and reproductive difficulties, stays on the national row. It does not move onto simazine, whose health cell says problems with blood.

What Should a Best Available Technology Note Say?

Five lines keep the next visit from turning a column into a guarantee. If a line does not apply, mark it skipped.

1. The contaminant name and the CAS the lab printed, not a neighbor with a similar MCL.
2. Whether you are reading an MCL number or a TT. The footnote treats those as different definitions.
3. Which of the three organic columns are marked, and which are empty, if the row is on table 2.
4. Whether the sample is a public system the section names, or a private well the section does not name.
5. What you did not claim: no removal percent, no installed price, and no statement that an X sizes the tank in the basement.

Where the Column Sits on the Job

The lab sheet belongs with the customer, the address, and the date. A price for equipment is a later page. A city plant and a point-of-entry tank are not the same machine. If you sell carbon, say you sell carbon. If the row left carbon empty, do not describe the tank as the marked technology.

Paragraph (b) excepts PFAS from the three-column table. PFAS rows on the same Cornell section use a later table, with anion exchange, granular activated carbon, reverse osmosis, and nanofiltration named for the listed PFAS. That later table is not table 2. Do not copy a PFAS list back onto simazine, and do not copy simazine's single carbon mark onto a PFAS row.

How a dealer reads the whole panel is the well water testing guide. The 1,2-dichloroethane digits, kept apart from dichloromethane, are 1,2-dichloroethane in well water. The software that holds the customer file is water treatment contractor software. This article does not size a filter and does not say a sample passed.

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