Heptachlor Epoxide in Well Water: The 0.0002 mg/L Line

By SubcontractorHub Editorial Team·Published November 2026

A pesticide panel can list a parent chemical and a breakdown product on one page. The digit next to heptachlor epoxide is not the digit next to heptachlor, and it is not safe to borrow because another row also prints 0.0002. 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, and it is not medical advice.

The 0.0002 Line Is Not the Parent's 0.0004

EPA's national primary table, fetched the day this page was written, lists heptachlor epoxide with an MCLG of zero and an MCL of 0.0002 mg/L. The potential-effects cell says liver damage and an increased risk of cancer. The source cell says breakdown of heptachlor. Footnote 2 says units are milligrams per liter unless otherwise noted, and that milligrams per liter are equivalent to parts per million. This row did not opt out of that unit.

Heptachlor, on that same table, prints a goal of zero and an MCL of 0.0004 mg/L. Its health cell uses the same liver-damage sentence. Its source cell says residue of a banned termiticide. Sharing the health words is not sharing the digit, and sharing the parent name is not sharing the breakdown row. Quoting a bare 0.0002 without the name lets the next reader pick the parent, or pick a fumigant that happens to print the same MCL.

The parent row has its own page, heptachlor in well water. Lindane prints 0.0002 mg/L on both cells, with liver or kidney problems and a source cell that says runoff or leaching from insecticide used on cattle, lumber, and gardens. DBCP prints a goal of zero and an MCL of 0.0002 mg/L, with reproductive difficulties and an increased risk of cancer, and a source cell that says runoff or leaching from a soil fumigant used on soybeans, cotton, pineapples, and orchards. The opening sentence of the national page says these standards apply to public water systems. It does not name a single-home well.

What the Breakdown Note Holds

The goal cell is zero. The page defines an MCLG as the level of a contaminant in drinking water below which there is no known or expected risk to health. It says MCLGs allow for a margin of safety and are non-enforceable public health goals. Zero on this row is that kind of goal. It is not a lab result of zero, and it is not a statement that the well has no heptachlor epoxide.

The MCL cell is 0.0002 mg/L. The page defines an MCL as the highest level of a contaminant that is allowed in drinking water. It says MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration, and that MCLs are enforceable standards. That definition is the public rule's definition. It is not a price for a filter, and it is not a percent removed.

The health cell is liver damage and an increased risk of cancer, described as a potential effect of long-term exposure above the MCL. That sentence is the public table's cell. It is not a finding about a person in the house. If a customer asks what the number means for a person, the honest line is that this page is not medical advice. Do not swap in DBCP's reproductive sentence because the MCL digits match.

The source cell is breakdown of heptachlor. Keep that sentence on the epoxide. Do not shorten it to "heptachlor" and let the next reader pick the parent at 0.0004, whose source cell is a banned termiticide. The difference between a goal and an enforceable level is MCL and MCLG. Lindane's goal is 0.0002, not zero. This row's goal is zero.

No Removal Percent Is Printed Here

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 parent's 0.0004, or DBCP's fumigant sentence, from landing on a breakdown row that said 0.0002.

Best available technology, when a page names a mark, is explained in what is best available technology. No mark was fetched for heptachlor epoxide on this date, so none is printed. A carbon sentence copied from a neighbor is not this row. An insecticide row whose goal and MCL both read 0.002 is endrin in well water. That matched pair is not this zero.

What Should the Heptachlor Epoxide in Well Water Note Say?

Five lines keep the public pair from being rewritten as the parent chemical or as a private-well fine.

1. The contaminant name as the lab printed it, and not heptachlor and not DBCP and not lindane.
2. The result and the unit. If the unit is not milligrams per liter, do not drop the unit and call the result 0.0002.
3. The public pair you compared it with: MCLG zero and MCL 0.0002 mg/L, named as the national heptachlor epoxide row.
4. Whether the sample is a private well or a public system. The national page names public water systems. It does not name a single house.
5. What you did not claim: no removal percent, no installed price, no CAS, and no statement that 0.0002 mg/L is the parent's 0.0004 or lindane's matching goal.

Where the Row Sits on the Job

Heptachlor epoxide in well water 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 parent row next to it. Mixing the 0.0002 line into a carbon quote because the panel listed both names skips the breakdown sentence.

Both the goal and the MCL have to stay on the note. Zero is not the same kind of number as 0.0002. Dropping the goal because it says zero is how a later reader treats 0.0002 as if it were the goal too, which is lindane's pattern, not this one.

A breakdown sentence is easy to shorten. The parent's source cell is a banned termiticide at 0.0004. DBCP's source cell is a soil fumigant, and its MCL is also 0.0002 with a goal of zero. If the lab names the epoxide, keep the breakdown sentence attached. Do not average 0.0002 with 0.0004 because both names start with the same word.

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.

Frequently Asked Questions