Is an Aerius calculation also a permit requirement?

Almost every permit application for a construction project must now be accompanied by an Aerius calculation. This way it is clear whether the construction project will not cause any adverse (nitrogen) effects on Natura 2000 areas.
But what exactly is such an Aerius calculation in a legal sense?

First of all, the good news. In the second half of 2020, the provinces and the national government agreed with each other that construction projects that cause no more than 0.05 mol/h/year of nitrogen deposition during the construction phase will no longer be classified as requiring a permit. If the Aerius calculation shows that you remain below 0.05 mol/h/year, then you are over the first legal nitrogen hurdle and the shovel can perhaps be driven into the ground.

For the use phase of the project, it is a different story and, for the time being, it remains complicated, but it is not impossible to obtain a permit. Some habitat types in Natura 2000 areas are more sensitive to nitrogen deposition than others, and some areas are less heavily overburdened than others - or even not overburdened at all. If an Aerius calculation shows that a project in the use phase will lead to a small increase in nitrogen deposition on not too sensitive habitat types in not too heavily overloaded Natura 2000 areas, an ecologist can conclude in a pre-assessment (or appropriate assessment) that significant negative effects due to that project are excluded. The permit (with regard to the nitrogen aspect) can then be granted.

Problems with change of use related to licensed situation?

But what if, a year after completion, you want to change the way you use it? Maybe you're completely fed up with the troubles of that new heat pump and just want a reliable old-fashioned boiler again. Is that possible or do you need a new natural gas permit?

The premise is that a permit is granted for a project that consists of certain activities that are prohibited from being carried out without that permit. From both the permits and the associated applications, it can be deduced what activities a particular project consists of. Contrary to what may be thought, there is no obligation for the competent authority to stipulate a certain nitrogen deposition or nitrogen emission in the permit. So a permit does not so much give an independent right to a certain nitrogen deposition, but an independent right to perform activities that result in nitrogen deposition.

So whether you can substitute that heat pump for a central heating boiler depends on what the permit says and how that permit was applied for. Then the Aerius calculation suddenly turns out to be very important. Indeed, if the permit states that it was granted in accordance with the application, the Council of State treats that Aerius calculation as a permit requirement that counts as an emission ceiling (ABRvS 1 July 2020, ECLI:NL:RVS:2020:1528, r.o. 5-5.2). That means that to install that central heating boiler you have to internally offset within the space you have according to the Aerius calculation. If you design the activities at the time of the application in such a way that the lowest possible nitrogen deposition rolls out of the Aerius calculation, you can therefore suffer a disadvantage when you change your business operations later.

Solution?

To cover this risk, you can ask the competent authority in your application not to make the Aerius calculation part of the permit and not to include emission requirements in the permit. This is because the competent authority does not legally have to include this in the permit (but may). We expect that not including emission requirements will ultimately lead to more legal certainty. This is because the way in which nitrogen emissions and nitrogen depositions are calculated is periodically changed to reflect the latest scientific insights, as happened on October 15 of this year with the update of the Aerius Calculator. Because the method of calculation changes, it is possible that a project now results in more nitrogen deposition than at the time of application, while the project itself has not changed. The inclusion of emission requirements in a permit can therefore lead to uncertainty and legal hassle year after year without really having changed anything. We assume that the competent authority does not want this either.