Title
Comparison of selection methods to deduce natural background levels for groundwater units
Author
Griffioen, J.
Passier, H.F.
Klein, J.
TNO Bouw en Ondergrond
Publication year
2008
Abstract
Establishment of natural background levels (NBL) for groundwater is commonly performed to serve as reference when assessing the contamination status of groundwater units. We compare various selection methods to establish NBLs using groundwater quality data forfour hydrogeologically different areas in the highly populated and developed subcatchment Western River Rhine, The Netherlands: selection of old groundwater (before 1945), of tritium-free groundwater (i.e., infiltrated before 1950), and of groundwater having no agricultural contamination by NO3 and SO4. Differences as well as similarities in percentile valuesfor Cl, NH4, and SO 4 concentrations are observed among the selection methods as well as the spatial units, pointing out that selection of the data set is a crucial step in deducing NBLs. The following general points of attention are deduced: (1) reference to composition of recharge water (rain or river infiltrate) is necessary to confirm the statistical outcomes, (2) old analyses are affected by conservation errors after sampling for redox-sensitive solutes and may be obtained by selective sampling, (3) old analyses are the only direct reference for NBLs for groundwater units having only anthropogenically influenced, young groundwater at present and (4) establishment of a priori percentile values as maximum NBL is not right and confirmation by additional process-based insight in the controls on water composition is necessary. © 2008 American Chemical Society.
Subject
Geosciences
Contamination
Groundwater
Hydrogeology
Image segmentation
River pollution
Tritium
Underground reservoirs
Water quality
Agricultural contamination
Ground water quality
natural backgrounds
Netherlands
River Rhine
selection methods
Sub catchments
Groundwater pollution
ammonia
chloride
chlorine
ground water
nitrite
rain
sulfate
tritium
comparative study
groundwater pollution
nitrate
recharge
redox potential
water quality
agriculture
article
chemical composition
concentration (parameters)
geology
hydrodynamics
intermethod comparison
natural background level
Netherlands
oxidation reduction reaction
river
sampling
solute
water contamination
water quality
Chlorides
Environmental Monitoring
Fresh Water
Geology
Netherlands
Quaternary Ammonium Compounds
Sulfates
Water Pollutants, Chemical
Eurasia
Europe
Rhine River
To reference this document use:
http://resolver.tudelft.nl/uuid:c8db1294-3cde-4549-ba8d-7a89ed454c37
TNO identifier
240897
ISSN
0013-936X
Source
Environmental Science and Technology, 42 (13), 4863-4869
Document type
article