SEGH Articles

Flux Based Management of a Groundwater Pollution: from Mass Flux Measurements to Regulatory Decisions

01 August 2011
Goedele Verrydt won the Springer / Hemphill Prize for Student Oral Presentation at SEGH 2011 in Ormskirk, UK.


Goedele Verreydt, M.Sc. in Environmental Engineering (2004), commenced her PhD in the Department of Biology at the University of Antwerp in January 2008. Her PhD research concerns the determination and calculation of groundwater contaminant mass fluxes in the frame of a groundwater management, which she performs in the research group Land and Water Management at the Flemish Institute for Technological Research (VITO), Mol, Belgium.

The management of contaminated groundwater is very challenging. Most decisions regarding groundwater pollutions are driven by contaminant concentrations. Since concentration estimates may be highly uncertain and do not include the fluctuations caused by spatially and temporally varying hydrologic conditions, these strategies can be improved by additionally considering contaminant mass fluxes (mass of contaminants passing per unit time per unit area) and contaminant mass discharges (sum of all mass flux measures across an entire plume). The contaminant mass that effectively reaches a downgradient receptor, determines the actual risks for the receptor and should therefore be monitored on site. The combined monitoring of contaminant mass fluxes and groundwater fluxes along a control plane is possible with Passive Flux Meters (PFMs), recently developed passive sampling devices that are installed in monitoring wells for a certain period of time.


The main objectives of this study are:

  • to delineate a robust interpretation method for the measurement and calculation of groundwater contaminant fluxes, based on mass flux measurement with Passive Flux Meters (PFMs);
  • to define a clear strategy that supports regulatory decisions in a flux and risk based groundwater management.

The PFM consists of a permeable sorbent infused with soluble tracers packed in a nylon mesh tube. The measurements of the captured contaminants and the remaining resident tracer on the sorbent are used to estimate respectively contaminant and groundwater fluxes.

To calibrate and validate the PFMs, lab as well as field experiments are performed. In addition, the measured water fluxes and contaminant mass fluxes are compared to the results obtained by traditional measurement techniques. The proposed management strategy is based on a source-path-receptor approach.

The PFM has proven to be a valuable instrument for the measurement of contaminant mass flux in groundwater. The extrapolation options of the PFM flux data are defined. Mass discharge can be estimated by integrating the PFM mass flux data throughout the control plane, which converts the individual flux values to a time-stamped cumulative flux (or discharge value). Further, a theoretical framework for a flux based management strategy is set by introducing the term CMDmax (maximum accepted contaminant mass discharge) at a predefined plane of compliance, i.e. a control plane orthogonal to the main flow direction and upgradient the receptor. The proposed strategy includes remedial action if the CMDmax is exceeded.

 G. Verreydt1,2, I. Van keer1 and J. Bronders1

1VITO, Land and Water Management, Boeretang 200, 2400 Mol, Belgium

2Artesis University College of Antwerp, Paardenmarkt 92, 2000 Antwerpen

 Figure shows Mrs. Verreydt retrieving a PFM during a field demonstration in Rijmenam, Belgium.

 Annable, L.D., K. Hatfield, J. Cho, H. Klammler, B.L. Parker, J.A. Cherry and P.S.C. Rao. 2005. Field-Scale Evaluation of the Passive Flux Meter for Simultaneous Measurement of Groundwater and Contaminant Fluxes. Environmental Science & Technology 39(18): 7194-7201.     

Verreydt, G., Bronders, J., Van Keer, I., Diels, L. & Vanderauwera, P. (2010) Passive samplers for monitoring VOCs in groundwater and the prospects related to mass flux measurements. Ground Water Monitoring and Remediation 30(2): 114-126.

Keep up to date

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • Improving arsenopyrite oxidation rate laws: implications for arsenic mobilization during aquifer storage and recovery (ASR) 2018-04-25


    Aquifer storage and recovery (ASR) and aquifer recharge (AR) provide technical solutions to address water supply deficits and growing future water demands. Unfortunately, the mobilization of naturally present arsenic due to ASR/AR operations has undermined its application on a larger scale. Predicting arsenic mobility in the subsurface during ASR/AR is further complicated by site-specific factors, including the arsenic mobilization mechanisms, groundwater flow conditions, and multi-phase geochemical interactions. In order to ensure safe and sustainable ASR/AR operation, a better understanding of these factors is needed. The current study thus aims to better characterize and model arsenic remobilization at ASR/AR sites by compiling and analyzing available kinetic data on arsenic mobilization from arsenopyrite under different aqueous conditions. More robust and widely applicable rate laws are developed for geochemical conditions relevant to ASR/AR. Sensitivity analysis of these new rate laws gives further insight into the controlling geochemical factors for arsenic mobilization. When improved rate laws are incorporated as the inputs for reactive transport modeling, arsenic mobilization in ASR/AR operations can be predicted with an improved accuracy. The outcomes will be used to guide groundwater monitoring and specify ASR/AR operational parameters, including water pretreatment requirements prior to injection.

  • Heavy metal exposure has adverse effects on the growth and development of preschool children 2018-04-25


    The purpose of this study was to investigate the associations between levels of lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn) in the PM2.5 and blood and physical growth, and development parameters including birth length and weight, height, weight, body mass index (BMI), head circumference, and chest circumference in preschool children from Guiyu (e-waste exposure area) and Haojiang (the reference area). A total of 470 preschool children from Guiyu and Haojiang located in southeast coast of China were recruited and required to undergo physical examination and blood tests during the study period. Birth length and weight were obtained by birth records and questionnaire. Pb and Cd in both PM2.5 and blood were significantly higher in Guiyu than Haojiang. Remarkably, the children of Guiyu had significantly lower birth weight and length, BMI, and chest circumference when compare to their peers from the reference area (all p value < 0.05). Spearman correlation analyses showed that blood Pb was negatively correlated with height (r = −0.130, p < 0.001), weight (r = −0.169, p < 0.001), BMI (r = −0.100, p < 0.05), head circumference (r = −0.095, p < 0.05), and chest circumference (r = −0.112, p < 0.05). After adjustment for the potential confounders in further linear regression analyses, blood Pb was negatively associated with height (β = −0.066, p < 0.05), weight (β = −0.119, p < 0.001), head circumference (β = −0.123, p < 0.01), and chest circumference (β = −0.104, p < 0.05), respectively. No significant association between blood Cd, Cr, or Mn was found with any of our developmental outcomes. Taken together, lead exposure limits or delays the growth and development of preschool children.

  • Contamination characteristics of trace metals in dust from different levels of roads of a heavily air-polluted city in north China 2018-04-24


    Concentrations of eight trace metals (TMs) in road dust (RD) (particles < 25 μm) from urban areas of Xinxiang, China, were determined by inductively coupled plasma mass spectrometry. The geometric mean concentrations of Zn, Mn, Pb, As, Cu, Cr, Ni and Cd were 489, 350, 114, 101, 60.0, 39.7, 31.6, and 5.1 mg kg−1, respectively. When compared with TM levels in background soil, the samples generally display elevated TM concentrations, except for Cr and Mn, and for Cd the enrichment value was 69.6. Spatial variations indicated TMs in RD from park path would have similar sources with main roads, collector streets and bypasses. Average daily exposure doses of the studied TMs were about three orders of magnitude higher for hand-to-mouth ingestion than dermal contact, and the exposure doses for children were 9.33 times higher than that for adults. The decreasing trend of calculated hazard indexes (HI) for the eight elements was As > Pb > Cr > Mn > Cd > Zn > Ni > Cu for both children and adults.