An existing soil report was prepared for a commercial site. In future children are to play there and vegetables are to grow. The fact that the document names the same plot does not yet mean it fully answers the new question. Decisive is which use and which contact with the soil were investigated.
Do not treat the garden as a single homogeneous area
Describe the intended areas: seating area, play area, beds or a still paved driveway. Note known past uses and existing investigations, each with their spatial extent. Unknown areas should remain identifiable. A neat drawing must not make a missing investigation look like an unremarkable finding.
The Federal Soil Protection and Contaminated Sites Ordinance distinguishes different exposure pathways and uses in investigations. § 11 lists, for the soil–human pathway, among others, children’s play areas and residential areas, and for the soil–edible-plant pathway, among others, kitchen gardens. For the scope of investigation, available information and local circumstances are to be taken into account. [BODEN11] This does not result in private guidance on the number of samples, but rather a more precise request to professionals.
Have existing reports read with a purpose
Our editorial recommendation: hand over the complete report with appendices. Ask for a statement on which planned uses are already covered and which require additional assessment. Ask about location, investigated layers, substances considered and the objective of the investigation at that time. You do not need to interpret these details yourself.
A short results paragraph can lack important context. That is why a single page is not re-labelled as an alleged general “soil clearance”. An investigation of only part of an area is also not transferred to the adjacent garden without professional justification.
Formulate an investigation brief with a decision
The brief should explain what is to be decided: for example, whether the planned garden use can be assessed on the basis of the existing findings and which investigation is missing, if any. Ask the professional to explain the limits of statement of the proposed scope. The cheapest standard package possible is not a helpful choice if its results do not answer the use question.
Digging, distributing or removing suspect material independently can raise additional questions. Coordinate necessary work in advance with the responsible authorities and professionals. This text does not recommend independent remediation or laboratory threshold values for lay decisions.
Example: lawn report and vegetable bed
A family receives an investigation for a limited recreational area. In a corner not previously included they later want to create beds. They mark the additional area and describe the planned use. The follow-up question is now whether the existing state of knowledge supports that; it is not which single number in the report looks most favourable.
Store the outcome in an understandable way
Keep the brief, the investigated areas and the professional response together. The completion note should state which use was assessed and which conditions apply. If a use later changes, it will first be checked whether that assessment still fits. A garden plan is not made risk-free by this, but its open soil questions remain comprehensible.