No industrial operation gets stuck at the roof. It gets stuck underground. A sale, an extension, a change of use or the closure of an activity can proceed smoothly until the day someone asks what is beneath the slab. From that moment on, the calendar is no longer dictated by negotiation: it is dictated by an investigation that was not anticipated.
The question can no longer be postponed
Law 7/2022, of 8 April, on waste and contaminated soils for a circular economy, dedicates Title VIII to contaminated soils. Its article 98.3 obliges landowners to declare, in the title of any transfer of a real right, whether any potentially soil-contaminating activity has taken place or not. The same declaration is required in new construction statements.
Which activities are considered so is not debatable. They are those listed in Annex I of Royal Decree 9/2005, of 14 January, identified by their CNAE code, in the version updated by Order PRA/1080/2017.
The problem, therefore, is rarely regulatory. It is a work order issue. Those who start drilling end up paying for two investigations: the first, to discover that they did not know where to sample; the second, to do it correctly.
The method, in six steps
1 · Document screening before touching the ground. CNAE crossed with Annex I of RD 9/2005; historical uses based on orthophotos, licenses and environmental authorisation; inventory of deposits, buried pipes and dumping points. It is two or three weeks of office work that saves months of fieldwork.
2 · Conceptual model of the site before the first sample. Source, pathway and receptor: what substance, how it can move and who or what may be exposed. If the three columns cannot be written, it is still not known where to drill; only where it is more convenient is known.
3 · Read what has been declared and what has not. The preliminary situation report (article 3 and annex II of RD 9/2005) and the subsequent situation reports are the documentary record of the site. They include the declared activities, the products, and the dates. The silence of a specific year is also information.
4 · Investigation in phases, not by grid. First, an exploratory phase directed at the hypotheses of the conceptual model. Then, if necessary, a detailed phase to delineate the impact. A regular grid without hypotheses is expensive and often blind: it may leave just the focus that was sought between two points.
5 · Exceeding an NGR does not mean having contaminated land. The generic reference levels of annex V (human health) and annex VI (ecosystems) of RD 9/2005, with the metals set by each autonomous community, are a screening threshold. Exceeding them opens the quantitative risk analysis; it does not close it.
The acceptable risk criterion is set by article 2 of the same decree. For carcinogenic substances, an expected cancer frequency not exceeding one case per one hundred thousand exposed persons. For systemic effects, a ratio between exposure dose and maximum allowable dose of less than one.
6 · Decide with scenarios and dates, not with a figure. Voluntary recovery (article 102 of Law 7/2022) or procedure for declaring contaminated land (article 99). Scope, deadlines, and who is responsible according to the order of precedence of article 100. Three scenarios with cost and schedule are worth more than a single estimate.
What changes if it is done in this order
One stops asking "how much will it cost" and starts answering "how much does each scenario cost, and when". It is the information that a buyer needs to set a price, a seller to avoid dragging an open contingency, an industry to expand without halting work, and an administration to authorise a change of use with criteria.
And it is, above all, information that arrives before the signing, not after.
How we work at auma
At auma we organise soil investigation in this sense: first the office, then the model, then the field. Thirty-three years without a matrix or product to place allow us to recommend only what needs to be measured. If you have an operation on a site with an industrial history, let's discuss it before the first drilling.
Rigor is not analysing more samples. It is knowing which ones.