Why an expert opinion is addressed even for source changes
An expert opinion is one of the main expert supporting documents for permitting listed stationary air pollution sources. It is not a formal annex. It is intended to verify how the source is classified, which pollutants arise, which emission limits and technical conditions apply to it, how emissions will be determined, and whether the proposed solution meets the requirements of the Air Protection Act.
For a new source the need for an expert opinion is usually clear. A more difficult question arises for changes to an existing source. The operator often assumes that if the source is already permitted, notification or a simple permit change will be enough. That may not apply.
What matters is not whether the source already exists, but what impact the planned change has on designed output, capacity, emissions, or operating conditions.
If capacity increases with the change, technology is added, fuel changes, the exhaust is modified, filtration changes, or new emissions arise, the regional authority may require an expert opinion as supporting material for proceedings on a change of operating permit.
Basic rule under the law
The Air Protection Act proceeds from the principle that an expert opinion is submitted for proceedings on issuing or changing an operating permit, unless proceedings are conducted under another legal regulation to which this supporting document is submitted.
The law also sets exceptions. For practice the most important exception concerns certain changes of operating permit. An expert opinion is generally not required for changes in which designed output or capacity does not increase and emissions do not increase.
This exception does not apply, however, if the proceedings concern setting an operating technical condition replacing a specific emission limit.
| Situation | Expert opinion |
|---|---|
| new listed source | generally yes |
| source change with increase in designed output | generally yes |
| source change with increase in designed capacity | generally yes |
| change leading to increase in emissions | generally yes |
| change without increase in capacity, output, or emissions | usually no |
| setting technical condition instead of specific emission limit | yes, even if there is otherwise no increase |
| permitting of newly classified source | generally yes |
In practice: if the operator can demonstrate that the change does not increase output, capacity, or emissions and does not involve replacement of an emission limit by a technical condition, an expert opinion is often not needed. If they cannot demonstrate this, the authority may require it.
When a change increases output, capacity, or emissions
An increase in output or capacity is not always obvious. It may involve installation of a new line, addition of another spray booth, expansion of crushing technology, increase in consumption of organic solvents, increase in boiler plant input, addition of another welding workplace, or enlargement of the handling area.
An increase in emissions also does not mean only a higher concentration in the exhaust. Emissions may increase, for example, because the source will run longer, process more material, consume more fuel or solvents, will have higher waste air flow, or the efficiency of the separation equipment changes.
| Type of change | Why it may be significant |
|---|---|
| addition of new technology | may increase capacity and emissions |
| increase in operating hours | annual emissions may rise even without equipment change |
| change of fuel | may change the composition of pollutants |
| change of coating materials | may change VOC and TOC emissions |
| change of filtration | may affect compliance with emission limits |
| new exhaust | changes the way emissions are discharged and dispersed |
| increase in storage or handling areas | may increase dust |
| change of raw materials | may change type and quantity of emissions |
It is important to distinguish a technical change that merely restores the original state from a change that actually expands operation or alters its emission parameters.
Expert opinion when technology changes
A technology change is a typical case where an expert opinion may become an important supporting document. It is not only a question of whether the equipment name changes. What matters is whether the character of emissions, emission limit, method of measurement, technical conditions, or source classification changes.
Example: a paint shop replaces part of its coating materials with another system. If consumption of organic solvents decreases and capacity and emissions do not change, it may be a change without need for an expert opinion. If, however, a new booth is installed at the same time, VOC consumption increases, exhausts change, or drying is added, an expert opinion may be necessary.
The same applies to a wood-processing operation, welding shop, boiler plant, recycling line, or waste facility. It is always necessary to assess whether it is a change with an impact on the level of pollution.
When the exhaust or filtration changes
A change of exhaust or filtration is often important for the authority even when the technology itself does not change. The exhaust determines where and how emissions are discharged. Filtration or separation equipment, in turn, determines what emissions will actually leave into the air.
If, for example, a filter is replaced with another type, separation efficiency changes, bypass is added, flow changes, or the measuring location is adjusted, it may be necessary to demonstrate expertly that the source will still meet permit requirements and legal regulations after the change.
Particular attention should be paid to the following changes:
- new or relocated exhaust,
- change of chimney height,
- change of waste air flow,
- change of filtration equipment,
- change of separator or afterburner unit,
- change of measuring location,
- change in the way emissions are extracted from the hall,
- transition from recirculation to discharge into outdoor air.
For these changes not only the emission limit is addressed, but also representativeness of measurement, dispersion of emissions, operating records, and operating conditions.
Technical condition instead of emission limit
Special attention is required when an operating technical condition replacing a specific emission limit is set in the operating permit. In that case the exception from the obligation to submit an expert opinion does not apply.
This is logical. If compliance is not to be assessed directly by emission limit but by a technical condition, it must be justified expertly why such an approach is appropriate, what measures are to be set, and how their compliance will be controllable.
This may involve, for example, a specific operating regime, dust reduction measures, monitoring of filtration equipment, limitation of handling, sprinkling, covering, an operating parameter, or another controllable condition. Such a condition must not only be written, but also technically defensible.
If a technical condition is to replace an emission limit, it must be clear why it is sufficient, how it will be controlled, and how it will ensure an acceptable level of emissions.
Retroactively permitted sources: beware the difference between change and new permit
Current methodological interpretations of the Ministry of the Environment point out that for some existing operations it may not in fact be only a change to an existing permit. It may be a situation where a certain activity or area was previously only described but was not actually permitted as an independent stationary source.
A typical example is some handling areas and deposits of bulk materials that newly fall under code 12.1 of Annex 2 to the Air Protection Act. The Ministry of the Environment distinguishes whether the source is expressly permitted in the operative part of the decision, or is only mentioned in the reasoning, operating description, or as a related activity.
| Status in the decision | Practical effect |
|---|---|
| source is expressly permitted in the operative part | may be a change to existing permit |
| source is only described in the reasoning | may not be regarded as a permitted source |
| source is listed as a related activity | it is necessary to verify whether it was actually permitted |
| source was previously unlisted and is now in Annex 2 | new operating permit may be necessary |
| source is part of another already permitted source | depends on whether this is clear from the decision |
For newly permitted "retroactively permitted" sources an expert opinion is generally required, because it is not a simple permit change without increase. It is issuing an operating permit for a source that newly falls under the regime of listed sources.
When an expert opinion is usually not needed
Not every operational change automatically means an obligation to submit an expert opinion. If it is an administrative change, clarification of data, change of operator name, update of description without impact on emissions, or replacement of equipment with an emission-comparable unit without increase in capacity, an expert opinion may be unnecessary.
As a rule, however, it must be demonstrable that the emission impact of the source does not really change. It is not enough merely to state that "the source will be the same". The authority may want technical supporting materials, comparison of original and new state, manufacturer data, balance, emission calculation, or a brief expert statement.
| Change | Expert opinion usually not needed if |
|---|---|
| equipment replacement | new equipment has no higher output, capacity, or emissions |
| update of operating rules | it is not a change of emission conditions |
| change of records | operating regime or emissions do not change |
| change of operator name | it is not a technical change of the source |
| filter replacement with equivalent unit | efficiency and operating conditions remain the same |
| clarification of exhaust description | the actual way of discharging emissions does not change |
Even in these cases it is advisable to have supporting materials ready that will defend the conclusion.
What the operator should check before submitting the application
Before submitting an application for a change of operating permit it is advisable to carry out a simple technical-legislative check. The aim is to find out whether it will be a change requiring an expert opinion, or whether it can be justified that the exception applies.
Basic check questions:
| Question | Why it matters |
|---|---|
| Is designed output increasing? | if yes, expert opinion is usually needed |
| Is designed capacity increasing? | capacity is one of the main decisive parameters |
| Are emissions increasing? | not only concentration but also mass flow and operating hours decide |
| Is the exhaust or chimney changing? | dispersion and measurability of emissions may change |
| Is filtration or separation changing? | compliance with emission limits may change |
| Are fuel, raw materials, or chemical substances changing? | type of emissions may change |
| Is a technical condition being set instead of a limit? | expert opinion is an essential supporting document |
| Is the source actually permitted in the operative part? | if not, it may be a new permit, not only a change |
This check helps avoid a situation where the authority suspends the proceedings and requests an expert opinion subsequently.
Why a general statement "emissions will not increase" is not enough
If the operator wants to use the exception from the obligation to submit an expert opinion, they should be able to demonstrate that the change really does not lead to an increase in designed output, capacity, or emissions. A general sentence in the application is usually not enough.
Documentation may take different forms depending on source type. For a boiler plant this will be input, fuel, operating hours, and emission parameters. For a paint shop, consumption of organic solvents, exhausts, and VOC balance. For a recycling line, capacity, operating hours, dust, and measures. For a wood-processing operation, material consumption, filters, exhausts, and TSP emissions.
Practically important: if an increase in emissions is not ruled out unambiguously, the authority may require an expert opinion as supporting material for a qualified decision.
Impact on project schedule
An expert opinion needs to be addressed in time. The author needs technical supporting materials, project documentation, technology parameters, exhausts, filters, raw materials, fuels, operating regime, emission data, and the existing operating permit. If the opinion is addressed only after an authority request, the proceedings are unnecessarily delayed.
For changes to an existing operation it is also important that an application for a change of permit must be submitted before implementing the change. Subsequent legalisation of a change is procedurally and communicatively worse than preliminary verification of the scope of supporting materials.
Most common mistakes
The most common mistake is treating a technical change as an insignificant administrative adjustment. The operator replaces equipment, changes the exhaust, increases operating hours, or adds technology and assumes the permit will "just be updated". From an air-quality perspective, however, it may be a change with an impact on emissions.
The second common mistake is underestimating capacity. Designed capacity is not assessed according to what is currently being produced, but according to what the source is capable of according to the project. The third mistake is an unclear relationship to the existing permit. If the source is not actually permitted in the operative part, it may not be a change to an existing permit but a new operating permit.
The fourth mistake is late addressing of the expert opinion. If the authority requests it only in suspended proceedings, time is lost that could have been saved by preliminary checking.
Summary
The authority may require an expert opinion even for a change to an existing source especially when the change increases designed output or capacity, increases emissions, changes emission-significant technology, exhaust, filtration, fuel, or operating regime. An expert opinion is also necessary where an operating technical condition replacing a specific emission limit is being set.
Conversely, for changes that do not increase output, capacity, or emissions and do not change essential emission conditions, an expert opinion is often not needed. The operator must, however, be able to demonstrate this conclusion. For retroactively permitted sources it is also necessary to verify whether it is truly a change to an already permitted source, or a new permit for a source that was previously only described or newly classified in Annex 2 to the law.
Send us the existing operating permit, description of the intended change, equipment data sheets, data on capacity, exhausts, filtration, fuel, raw materials, and operating hours. We will verify whether an expert opinion, change of operating permit, dispersion study, or other supporting document for the regional authority may be needed.
Factual basis of the article
The article is based mainly on the following sources:
- Act No. 201/2012 Coll., on air protection,
- Section 11(7) of Act No. 201/2012 Coll. – expert opinion,
- Air protection updates – Ministry of the Environment,
- Ministry of the Environment communication on application of code 12.1 of Annex 2 to the Air Protection Act,
- Act No. 42/2025 Coll., amending the Air Protection Act.
Under Section 11(7) of Act No. 201/2012 Coll., an expert opinion is submitted for proceedings on issuing or changing an operating permit, unless proceedings are conducted under another legal regulation. The exception applies, among other things, to proceedings on changes of operating permit in which designed output or capacity does not increase and emissions do not increase; this exception does not apply, however, to proceedings on setting an operating technical condition replacing a specific emission limit. The Ministry of the Environment communication on code 12.1 further explains that for newly permitted retroactively permitted sources an expert opinion is generally required, because it is not a simple change to an already permitted source.