What Is the Ground Water Rule?

By SubcontractorHub Editorial Team·Published October 2026

Dealers who work around wells hear the words sanitary survey and assume every well is under the same federal visit. The Ground Water Rule is a public-system rule. A house with one well is a different conversation unless that house meets the public-system definition the guidance manual prints. SubcontractorHub is software for the customer record. This page is the rule. It is not a treatment design, and it is not a finding that a jug of water is safe.

What a sanitary survey is, as its own page, stays on what is a sanitary survey. The rule for surface water and ground water under the direct influence of surface water stays on what is the Surface Water Treatment Rule. Who counts as a public water system stays on what is a public water system.

Four Duties, Not One Lab Result

EPA's sanitary survey guidance manual for ground water systems, document 815-R-25-016, modified August 2026 and fetched the day this page was written, says the Ground Water Rule applies to all public water systems that serve ground water, including consecutive systems that serve ground water from a wholesale system. It does not apply when a system combines all of its ground water with surface water, or with ground water under the direct influence of surface water, before treatment that meets the surface-water requirements.

The same section lists four requirements. The state conducts sanitary surveys that have a minimum scope and frequency and that identify significant deficiencies. Systems that do not provide 4-log treatment of viruses, and that have a total-coliform-positive sample in the distribution system, do triggered source-water monitoring. Any system with a significant deficiency or a fecal-indicator-positive source-water sample takes corrective action. Systems that provide 4-log treatment of viruses do compliance monitoring of that treatment.

A footnote on that page says a public water system serves at least 15 service connections or regularly serves at least 25 people at least 60 days a year. That is the definition attached to the rule in the manual. It is not a sentence about one household. If the customer is a single house, say so. Do not file this rule as if the house were a public system.

What the Ground Water Rule Note Holds

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 a surface-water sentence, or a private-well hardness number, from being filed as the Ground Water Rule.

Eight Elements on the Survey

The final-rule text, fetched the same day from EPA's NEPIS copy of the Ground Water Rule, names eight critical components of the sanitary survey, to the extent they apply to that system. The guidance manual says those eight elements are the minimum scope, and that a state may phase the reviews as long as every applicable element is covered inside the required interval.

1. Source
2. Treatment
3. Distribution system
4. Finished water storage
5. Pumps, pump facilities, and controls
6. Monitoring, reporting, and data verification
7. System management and operation
8. Operator compliance with State requirements

The manual says community ground water systems are surveyed at least every three years, and non-community ground water systems at least every five years. If the state finds outstanding performance, or the community system provides 4-log treatment of viruses, the community survey may be at least every five years instead. Those frequencies are the survey clock. They are not a promise that a dealer visits a private well on the same calendar.

What Should the Ground Water Rule Note Say?

Five lines keep the next visit from treating a coliform hit, a hardness number, and a surface-water rule as the same duty. Name the system, name which of the four requirements you are talking about, and say what you did not claim.

1. Whether the system is a public water system that serves ground water, using the manual's connection-or-population sentence.
2. Which duty you mean: the survey, the triggered source sample, the corrective action, or the 4-log compliance monitoring.
3. The survey clock you compared it with: every three years for a community system, every five years for a non-community system, unless the state has used the five-year community exception.
4. That 4-log, on the manual, is at least 99.99 percent treatment of viruses before or at the first customer. It is not a cartridge claim.
5. What you did not claim: no installed price, no private-well statute, and no statement that this rule is the Surface Water Treatment Rule.

Triggered Monitoring Is a Clock, Not a Filter

EPA's triggered-monitoring guidance, also fetched the day this page was written, says a ground water system that does not provide at least 4-log treatment of viruses before or at the first customer must sample when it is told a routine total-coliform sample is positive. Within 24 hours of that notice, it collects at least one sample from each ground water source that was in use when the positive routine sample was collected, unless the state has approved something else. The sample is analyzed for a fecal indicator the state specifies.

If that source sample is fecal-indicator-positive and the state does not invalidate it, the system takes corrective action when the state requires it, or it collects five additional source samples and analyzes those for a fecal indicator. The manual's corrective-action clock for a significant deficiency is 120 days, or a state-approved schedule. Missing that correction is a treatment-technique violation of the rule. Those sentences are about the public system and the state. They are not a script for a dealer standing at a kitchen sink.

The manual also says 4-log means at least 99.99 percent treatment of viruses, by inactivation, removal, or a state-approved combination, before or at the first customer, with compliance monitoring. Write 99.99 percent only when you mean that virus duty. Do not reuse it as a percent a carbon tank will remove a chemical. No chemical removal percent was fetched for this page, so none is printed.

Coliform on a private-well panel is a different article: coliform bacteria in well water. How a dealer reads the whole panel is the well water testing guide. The customer file still lives in 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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