How often you have to inspect a construction site, and what changes it

Inspection frequency is the requirement people ask about first and get wrong most, because it looks like a single number and is actually a small decision tree. Under EPA's 2022 Construction General Permit there are two routine options you may choose between, one condition that overrides the choice entirely, and one reduction available in dry climates.

The two routine options

If your site is not subject to the override below, you pick one of these and record which one you picked in your plan.

• Once every seven calendar days. Simple, predictable, and unaffected by weather. Part 4.2.1.
• Once every 14 calendar days, plus within 24 hours of a storm event producing 0.25 inches or more of rain. Fewer scheduled visits, but you now depend on knowing when it rained. Part 4.2.2.

The second option is chosen more often than it should be. It halves the scheduled visits, which is attractive on a long project, but it makes rainfall part of your compliance record: you need a way to know that a qualifying storm happened, and you need to be there within a day of it. On a site nobody visits at the weekend, a Saturday storm can put you out of compliance before Monday.

The override that beats both

If your site discharges to a sediment or nutrient impaired water, or to a Tier 2, 2.5 or 3 water, the increased frequency applies and the choice above disappears. That is once every seven calendar days AND within 24 hours of a storm producing 0.25 inches or more of rain in a 24 hour period, or within 24 hours of a snowmelt discharge from a storm producing 3.25 inches or more of snow. Part 4.3.1.

Read that as: both options at once, permanently. It is the single largest swing in inspection burden the permit contains, and it turns on a fact about the water you discharge to rather than anything about your site.

The override applies because of what your receiving water is, not because you knew about it. An operator who never checked is on the increased frequency and does not know it.

This is why the screening tool refuses to guess this input. If you have not checked, it returns an explicit unknown, tells you the answer changes if it turns out to be yes, and marks the receiving water screen unresolved. A tool that quietly assumed no would hand you a fortnightly schedule you were never entitled to.

How to find out

• Identify the water your site actually discharges to, including through a storm sewer that outfalls somewhere.
• Check whether it appears on your state's list of impaired waters for sediment or nutrients, published under Clean Water Act section 303(d).
• Check whether it carries a Tier 2, 2.5 or 3 antidegradation designation in your state's water quality standards.
• Record what you found and where you found it in the plan. The answer is part of the reasoning behind your schedule, and an inspector may ask.

The reduction you can earn

In arid, semi arid or drought stricken areas the permit allows a reduced frequency during the seasonally dry period: once per month, plus within 24 hours of a qualifying storm. It is not automatic. You must record the beginning and ending dates of the seasonally dry period in your plan, and outside those dates the ordinary frequency returns.

This is a real saving on a desert site and a trap on a site that is dry for part of the year. The reduction is tied to the dates you wrote down, not to the weather on the day.

The parts people forget

• The report deadline is separate from the inspection. You must complete the inspection report within 24 hours of completing the inspection. An inspection done on time and written up three days later is a finding.
• A qualified person has to do it. The permit requires the inspection to be carried out by a person who has completed the required training. This is not something a document generator can do for you, and any product implying otherwise is selling you a gap.
• Retention runs from the end of coverage. Inspection reports and the corrective action log must be kept for at least three years from the date coverage expires or is terminated, not three years from when the record was written. On a multi year project every record stays live for the whole project plus three years.

If a state permit governs

Everything above is EPA's permit. Most states run their own programme and issue their own construction general permit, which must be at least as protective but can be stricter, and several set different frequencies. Do not carry the federal numbers into a delegated state.

Where we have not read a state's permit, our state pages say so and link the agency rather than showing you the federal figures under a state heading. That gap is deliberate: the federal numbers are wrong in exactly the direction that gets people cited.