Arsenic concentrations after drinking water well installation: Time-varying effects on arsenic mobilization

Erickson, Melinda L.; Malenda, Helen F.; Berquist, Emily; Ayotte, Joseph D.

doi:10.1016/j.scitotenv.2019.04.362

Cited by 24 publications

(8 citation statements)

References 39 publications

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“…A few years later, after excavating the well, the Fe concentration decreased, while the Mn concentration remained at a high level. Erickson et al ( 2019 ) observed that well construction disturbs the aquifer and the geochemical balance of the groundwater and that the resulting geochemical disturbance affects the arsenic concentrations measured in the wells in northern–central parts of the USA. A similar phenomenon was recorded for Mn concentrations in the dug well in Enontekiö, northern Finland, after the well was excavated to make it deeper.…”

Section: Resultsmentioning

confidence: 99%

Variation in groundwater manganese in Finland

Kousa

Komulainen

Hatakka

et al. 2020

Environ Geochem Health

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Increasing evidence has emerged that Mn derived from drinking water could be a health risk, especially for children. This study aimed to provide more information on the variation in Mn concentrations in well water and factors that affect manganese concentrations in groundwater in the natural environment. The geochemical data consisted of analyses of single water samples (n = 5311) that were taken only once and data from monitoring sites where water samples (n = 4607) were repeatedly taken and analyzed annually from the same wells. In addition, the well-specific results from six wells at monitoring sites were described in detail. We obtained the data on water samples from the groundwater database of Geological Survey of Finland. In single samples, Mn concentrations varied from < 0.02 µg/l to 5800 µg/l in bedrock well waters and up to 6560 µg/l in Quaternary deposit well waters. Results from single water samples from bedrock wells and Quaternary deposit wells indicated that the dissolved oxygen content has an inverse association with the Mn concentration. When the dissolved oxygen O2 levels were lower, the Mn concentrations were higher. No clear association was found between the Mn concentration and the pH or depth of the well for single samples. Part of Mn was particle bound, because total Mn was higher than soluble Mn in most measured samples. In the monitoring survey, large variation in Mn concentrations was found in bedrock well water in Kemijärvi, 114–352 µg/l, and in dug well water in Hämeenkoski, 8.77–2640 µg/l. Seasonal and spatial variability in Mn concentrations in water samples from two bedrock wells was large at monitoring sites in northern Finland. Variability in the Mn concentrations in groundwater can be large, even in the same area. These data suggest that single measurements of the Mn concentration from a water source may not reveal the Mn status, and measurement of both the total and soluble Mn concentrations may be recommended.

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Section: Resultsmentioning

confidence: 99%

Variation in groundwater manganese in Finland

Kousa

Komulainen

Hatakka

et al. 2020

Environ Geochem Health

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“…In a study of 1245 public and private wells sampled twice, 87% of samples were within 4 μg/L; the remaining 13% showed larger variability, with the variability potentially related to seasonal variations in water levels or changes in the redox status of the groundwater (Ayotte et al 2015). During well installation, more oxidized water can enter an aquifer, which can become more reducing over time and arsenic levels can increase (Erickson et al 2019). In production wells, when the pumps are off, Fe oxides form that can sorb arsenic and lower concentrations which rebound during pumping (Erickson and Barnes 2006).…”

Section: Introductionmentioning

confidence: 99%

Recommended Sampling Intervals for Arsenic in Private Wells

Mailloux¹,

Procopio

Bakker

et al. 2020

Groundwater

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Geogenic arsenic in drinking water is a worldwide problem. For private well owners, testing (e.g., private or government laboratory) is the main method to determine arsenic concentration. However, the temporal variability of arsenic concentrations is not well characterized and it is not clear how often private wells should be tested. To answer this question, three datasets, two new and one publicly available, with temporal arsenic data were utilized: 6370 private wells from New Jersey tested at least twice since 2002, 2174 wells from the USGS NAWQA database, and 391 private wells sampled 14 years apart from Bangladesh. Two arsenic drinking water standards are used for the analysis: 10 µg/L, the WHO guideline and EPA standard or maximum contaminant level (MCL) and 5 µg/L, the New Jersey MCL. A rate of change was determined for each well and these rates were used to predict the temporal change in arsenic for a range of initial arsenic concentrations below an MCL. For each MCL and initial concentration, the probability of exceeding an MCL over time was predicted. Results show that to limit a person to below a 5% chance of drinking water above an MCL, wells that are ½ an MCL and above should be tested every year and wells below ½ an MCL should be tested every 5 years. These results indicate that one test result below an MCL is inadequate to ensure long‐term compliance. Future recommendations should account for temporal variability when creating drinking water standards and guidance for private well owners.

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“…Anoxic and mixed redox conditions were both commonly associated with high arsenic in domestic well water in western and central Minnesota (Erickson, Malenda, et al., 2019). Their study area was in the north central part of the GLAC (terrane 3B) where areas of mixed redox conditions are predicted (Figure 7) and where arsenic is associated with both solid‐phase iron sulfides (pyrite, arsenopyrite) and iron oxides (Nicholas et al., 2017).…”

Section: Resultsmentioning

confidence: 99%

“…Iron sulfides break down under oxic conditions, while iron oxides are vulnerable to dissolution under reducing conditions. Erickson, Malenda, et al (2019) showed that temporal changes in groundwater geochemistry can result in substantial changes in groundwater quality. Mixed redox conditions (Figure 7) can create a sensitive geochemical environment in which small geochemical shifts can result in substantial changes of water quality.…”

Section: Implications For Contaminants In This and Other Geologically Complex Unconsolidated Aquifersmentioning

confidence: 99%

Machine Learning Predicted Redox Conditions in the Glacial Aquifer System, Northern Continental United States

Erickson

Elliott

Brown

et al. 2021

Water Resources Research

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Groundwater supplies 50% of drinking water worldwide (Zekster & Everett, 2004) and 35% in the United States (Dieter et al., 2018); however, geogenic and anthropogenic contaminants can compromise water quality, limiting groundwater availability (Foster & Chilton, 2003;Nordstrom, 2002). Reduction/oxidation (redox) processes and redox conditions affect groundwater quality by influencing the toxicity, mobility and transport of common geogenic and anthropogenic contaminants (e.g., arsenic, manganese, and nitrate) through processes such as ion exchange, degradation, sorption, complexation, and mineral dissolution/ precipitation (Bohlke, 2002;McMahon, Belitz, et al., 2019;Welch et al., 2000). Spatial patterns in redox conditions, therefore, influence and inform spatial patterns of groundwater contaminants in aquifers important

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Arsenic concentrations after drinking water well installation: Time-varying effects on arsenic mobilization

Cited by 24 publications

References 39 publications

Variation in groundwater manganese in Finland

Variation in groundwater manganese in Finland

Recommended Sampling Intervals for Arsenic in Private Wells

Machine Learning Predicted Redox Conditions in the Glacial Aquifer System, Northern Continental United States

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