How to Request a Monitoring Waiver for IOC, SOC, and VOC

A monitoring waiver is a written decision from the state that you may sample some chemicals less often. It isn't a forever pass, and it isn't something you grant yourself because last year's results were clean.

The federal hooks are 40 CFR 141.23 for inorganic contaminants and 40 CFR 141.24 for volatile and synthetic organics, plus your state's analog. This page is how to ask, what to send, and what the state can do with the request. Confirm the current form with your primacy agency. This isn't legal advice.

What a waiver is and is not

A waiver reduces how often you sample a contaminant, or in a few cases (asbestos, cyanide) whether you sample it at all. It does not raise the MCL. It does not excuse a detect you already have. It does not cover every chemical on the lab menu.

Nitrate and nitrite are not waived the way SOCs and VOCs are. All public water systems monitor for nitrate under 141.23(d). The state can adjust some nitrate frequencies when results are reliably and consistently below the MCL. That is a frequency decision under the nitrate paragraphs, not a "stop sampling" waiver. Don't put nitrate in the same envelope as a VOC susceptibility request and expect one signature to cover both.

New sources are generally not eligible until initial monitoring on that source is complete. A well you brought online last fall does not inherit the waiver on the old well. The state will want the first rounds before it talks about less frequent work.

IOC, SOC, and VOC

Name the family you are asking about. The packet changes.

• IOC (inorganics). Metals and minerals under 40 CFR 141.23. See the IOC MCL list and monitoring schedule. Groundwater systems usually need at least three rounds, with at least one sample after January 1, 1993. Surface-water systems usually need at least three years. All previous results have to sit below the MCL.
• VOC (volatiles). The contaminants in 40 CFR 141.61(a). Community and non-transient non-community groundwater systems that do not detect those VOCs (detection here is at or above 0.0005 mg/L) may apply after initial monitoring. Surface-water systems have their own paragraph.
• SOC (synthetics). Pesticides and related organics in 40 CFR 141.61(c). States commonly use a "use" waiver (the chemical isn't used in the area) and a "susceptibility" waiver (the source is protected even if the chemical is used somewhere in the county). You have to show which one you are asking for.

Asbestos can be waived if the state agrees you are not vulnerable in source water and not vulnerable from asbestos-cement pipe. Cyanide can be waived if the state agrees there is no industrial cyanide source. Those are the two IOC items that can go to "no sample," not just "less often." Everything else is reduced frequency, and only if the state writes it down.

Vulnerability assessment, source protection, prior results

For VOCs and SOCs, the state reviews a vulnerability assessment. 40 CFR 141.24 points the state at previous monitoring, environmental persistence and transport, how well the source is protected (geology, well construction, setbacks), and proximity to potential contamination. Your source-water assessment is useful paper. It is not, by itself, the waiver.

This vulnerability assessment is not the AWIA risk and resilience assessment. The waiver write-up is about a chemical, a source, and a pathway.

Bring:

• The lab history for that contaminant at that source, including non-detects, with method and reporting level.
• Well logs or intake descriptions, grout, casing, sanitary seal, and the wellhead photos from the last sanitary survey.
• Land use and known chemical use within the area the state cares about: fuel tanks, dry cleaners, orchards, rights-of-way, industry.
• The current source-water assessment or protection plan, if you have one.
• Any change since the last waiver: a new well, a new interconnect, a change in pumping, a nearby spill.

If the source-water assessment says moderate or high susceptibility, say so. The state will see it anyway.

The packet you send

There is no national waiver form. The state has one, or it accepts a letter. Ask for this year's instructions before you assemble anything. Then send:

• The state's form or a signed letter that names the PWSID, the source IDs, and each contaminant or group you want waived.
• The basis: use, susceptibility, prior results below the MCL, or the specific IOC criteria in 141.23.
• The lab history and the vulnerability write-up.
• Who is signing (owner or authorized representative) and how the state can reach them.

40 CFR 141.23 says a decision to grant an IOC waiver shall be made in writing and shall set forth the basis. The state can start the review on its own, or you can apply. You specify the basis. Keep the written decision in the monitoring file. A verbal "you're fine on VOCs" from a former inspector is not a waiver.

A waiver is not a forever pass

Do not invent a term. The state sets the length. Federal rules only set outer bounds, and your state can be shorter.

For groundwater VOCs, 40 CFR 141.24 says a waiver shall be effective for no more than six years (two compliance periods). That is a cap, not a promise. The groundwater system still takes one sample at each sampling point during the waiver, and updates the vulnerability assessment. If the state does not reconfirm that the system is non-vulnerable within three years, the waiver is invalidated and annual sampling returns.

For many IOC waivers, 141.23 says sampling while the waiver is effective shall not be less frequent than once per nine-year compliance cycle. That is a ceiling on how thin sampling can get, not a term the state owes you. The state shall review the frequency when new data show up. A new detect, a new source, a land-use change, or unpaid fees can end the waiver.

How to ask, and what the state can do

Call or email the chemical-monitoring contact at the primacy agency and ask for the current waiver application. Put the PWSID in the subject line. Send the packet by the method the state accepts. Then wait for a written grant or a written denial.

The state can deny, grant a shorter term, grant SOCs and refuse VOCs, or revoke a waiver it already issued. If it denies or revokes, you return to the standard schedule on the date the letter says.

Track the remaining samples on a compliance calendar so the one sample you still owe during a VOC waiver does not become a monitoring violation. See How to build a water system compliance calendar and How to read your SDWIS violation record.

FAQ

Can I stop sampling because I have a waiver?

Only if the written decision says so, and only for the contaminants it names. Many waivers still require a sample during the waiver term. Asbestos and cyanide are the IOC cases that can go to no sample, and only if the state writes that down. Read the decision. Don't read the word "waiver" as "zero."

How long does a waiver last?

The state sets the term. Federal 40 CFR 141.23 and 141.24 set outer bounds for some waivers. They do not promise you those outer bounds. Ask the primacy agency for the date yours ends, and for the sample you still owe while it is in force.

Can the state revoke a waiver we already have?

Yes. New data, a new source, a failed vulnerability update, a detect, or a condition the state named in the decision can end it. When it ends, the standard schedule returns. The MCL never left.

Does a clean IOC history automatically get us a waiver?

No. Clean history is one input. The state still has to decide, in writing, with a basis. Groundwater systems generally need three rounds. Surface-water systems generally need three years. New sources wait until initial monitoring is done. Apply. Don't assume.

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Orevant provides compliance information tools. This page isn't legal advice. Confirm waiver eligibility, the packet, and the current term with your state primacy agency.