The authors regret that there were two statements in their original paper that could be misinterpreted and apologise for any inconvenience this may have caused. They have provided the following clarifications.
Figure 5
Panel (I) 7-day incidence for the sub-catchments of Drispensedt, Himmelsthür, and Itzum and for the region of Hildesheim. Panel (II) Normalised SARS-CoV-2 concentration in wastewater expressed as RNA-copies/(mL × Person). Panel (III) RNA concentration of SARS-CoV-2 in wastewater expressed in copies/mL.
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Panel (I) 7-day incidence for the sub-catchments of Drispensedt, Himmelsthür, and Itzum and for the region of Hildesheim. Panel (II) Normalised SARS-CoV-2 concentration in wastewater expressed as RNA-copies/(mL × Person). Panel (III) RNA concentration of SARS-CoV-2 in wastewater expressed in copies/mL.

Figure 5
Panel (I) 7-day incidence for the sub-catchments of Drispensedt, Himmelsthür, and Itzum and for the region of Hildesheim. Panel (II) Normalised SARS-CoV-2 concentration in wastewater expressed as RNA-copies/(mL × Person). Panel (III) RNA concentration of SARS-CoV-2 in wastewater expressed in copies/mL.
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Panel (I) 7-day incidence for the sub-catchments of Drispensedt, Himmelsthür, and Itzum and for the region of Hildesheim. Panel (II) Normalised SARS-CoV-2 concentration in wastewater expressed as RNA-copies/(mL × Person). Panel (III) RNA concentration of SARS-CoV-2 in wastewater expressed in copies/mL.

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In the Abstract of their original paper, the authors wrote:

‘Our study shows that sampling and analysis of virus concentrations in sub-catchments with particular settlement structures allows the identification of high concentrations of the virus at a local level in the wastewater, which are lower in samples collected at the inlet of the treatment plant covering the whole catchment.’

For clarification, this statement should read:

‘Our study shows that sampling and analysis of virus concentrations in sub-catchments with particular settlement structures can in some cases identify high virus concentrations at a local level, which are lower in samples taken at the inlet to the treatment plant covering the whole catchment.’

Justification: The virus concentration normalised by the number of inhabitants in copies/(mL × Person) presented in Figure 5 of the paper was always higher at the local sub-catchment level than at the inlet of the treatment plant. This statement is not true for all non-normalised concentrations in copies/mL, as can be seen from the new Figure 5 below. The authors have therefore added ‘in some cases’ to the sentence.

Figure 5 has been resupplied with an additional panel (Panel III), which has been added for the reader's better understanding of the dynamics of the virus in the catchment areas.

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In section 3.2.2 of their original paper, the authors wrote:

‘The concentration of SARS-CoV-2 in the wastewater at the inlet of the treatment plant (benchmark) showed the lowest values, indicating a loss of viral signal in the sewer, which can be explained by dilution (storm water and industrial wastewater discharges), viral decay and adsorption to sediment particles.’

For clarification, this statement should read:

‘The normalised concentration of SARS-CoV-2 in the wastewater at the inlet of the treatment plant (benchmark) showed the lowest values. The loss of viral signal in the sewer can be explained by dilution (storm water and industrial wastewater discharges), viral decay and adsorption to sediment particles.’

Justification: The sentence was missing the word ‘normalised’.

© 2025 The Authors
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