Groundwater chemistry data for status, risk, and trend analyses related to the fourth River Basin Management Plan (Vandområdeplan 4) - Documemtation report

This report documents the preparation of groundwater chemistry datasets for the fourth River Basin Management Plan 2027-2032 (Vandområdeplan 4, VP4), to be used primarily in the qualitative risk, status, and trend assessments. Additionally, some of the data could support the quantitative status assessments regarding groundwater quality impacts from abstraction. The work presented here is part of the project “Etablering af kemiske grunddata til Vandområdeplan IV”, funded by The Danish Agency for Green Transition and Aquatic Environment (Styrelsen for Grøn Arealomlægning og Vandmiljø, SGAV, 2025).

The purpose of the report is to serve as a technical documentation for the data-preparation including a detailed account of all decisions taken in this process. Therefore, the following data-preparation steps are described here: 1) extraction from Jupiter database, 2) cleaning including various quality checks and filtering procedures, 3) aggregation with annual mean (AM) and mean annual mean (MAM), 4) formatting of deliverables (data-products).