Tag Archives: groundwater

Radon in Groundwater, 12 Cities, China

Wu Y, Cui H, Liu J, Shang B, Su X. Radon Concentrations in Underground Drinking Water in Parts of Cities, China. Radiation protection dosimetry. 2017 Aug 31:1-5. doi: 10.1093/rpd/ncx121.

222Rn concentrations in underground drinking water samples in 12 cities from seven provinces (municipalities), China were determined by using a continuous radon monitor with air-water exchanger. A total of 73 underground water samples were collected. The observed radon levels were in a range of 1.0-63.8 Bq l-1, with a mean of 11.8 Bq l-1. The annual effective dose from inhalation of water-borne radon for average radon content in underground water was 72.6 μSv and for maximal observed radon concentration in underground water the corresponding dose was 393.8 μSv. The dose contribution of inhalation dose from water-borne radon should be paid attention in some granitic area.

Waterborne Norovirus Outbreaks in Two Undisinfected Groundwater Wells, Finland

Kauppinen A, Pitkänen T, Miettinen IT. Persistent Norovirus Contamination of Groundwater Supplies in Two Waterborne Outbreaks. Food and environmental virology. 2017 Oct 11. doi: 10.1007/s12560-017-9320-6.

Microbiological contamination of groundwater supplies causes waterborne outbreaks worldwide. In this study, two waterborne outbreaks related to microbiological contamination of groundwater supplies are described. Analyses of pathogenic human enteric viruses (noroviruses and adenoviruses), fecal bacteria (Campylobacter spp. and Salmonella spp.), and indicator microbes (E. coli, coliform bacteria, intestinal enterococci, Clostridium perfringens, heterotrophic plate count, somatic and F-specific coliphages) were conducted in order to reveal the cause of the outbreaks and to examine the effectiveness of the implemented management measures. Moreover, the long-term persistence of noro- and adenovirus genomes was investigated. Noroviruses were detected in water samples from both outbreaks after the intrusion of wastewater into the drinking water sources. In the outbreak I, the removal efficiency of norovirus genome (3.0 log10 removal) in the sand filter of onsite wastewater treatment system (OWTS) and during the transport through the soil into the groundwater well was lower than the removal efficiencies of E. coli, coliform bacteria, intestinal enterococci, and spores of C. perfringens (6.2, 6.0, > 5.9, and > 4.8 log10 removals, respectively). In the outbreak II, cleaning of massively contaminated groundwater well and drinking water distribution network proved challenging, and noro- and adenovirus genomes were detected up to 3 months (108 days). The long-term persistence study showed that noro- and adenovirus genomes can remain detectable in the contaminated water samples up to 1277 and 1343 days, respectively. This study highlights the transport and survival properties of enteric viruses in the environment explaining their potency to cause waterborne outbreaks.

Groundwater Quality in the United Arab Emirates

Zhang HW, Sun YQ, Li Y, Zhou XD, Tang XZ, Yi P, Murad A, Hussein S, Alshamsi D, Aldahan A, Yu ZB, Chen XG, Mugwaneza VDP. Quality assessment of groundwater from the south-eastern Arabian Peninsula. Environ Monit Assess. 2017 Aug;189(8):411. doi: 10.1007/s10661-017-6092-2.

Assessment of groundwater quality plays a significant role in the utilization of the scarce water resources globally and especially in arid regions. The increasing abstraction together with man-made contamination and seawater intrusion have strongly affected groundwater quality in the Arabia Peninsula, exemplified by the investigation given here from the United Arab Emirates, where the groundwater is seldom reviewed and assessed. In the aim of assessing current groundwater quality, we here present a comparison of chemical data linked to aquifers types. The results reveal that most of the investigated groundwater is not suitable for drinking, household, and agricultural purposes following the WHO permissible limits. Aquifer composition and climate have vital control on the water quality, with the carbonate aquifers contain the least potable water compared to the ophiolites and Quaternary clastics. Seawater intrusion along coastal regions has deteriorated the water quality and the phenomenon may become more intensive with future warming climate and rising sea level.

Ground Water Quality in Vietnam

Le Luu T. Remarks on the current quality of groundwater in Vietnam. Environmental science and pollution research international. 2017 Jul 24. doi: 10.1007/s11356-017-9631-z.

This paper reviews the current quality of groundwater in Vietnam. In Vietnam, groundwater is obtained primarily from tubewells, which have high concentrations of pollutants such as As, Fe, Mn, and NH4+. In the areas where groundwater tests were conducted, arsenic levels ranged from 0.1-3050 μg/L, which substantially exceed the standard of 10 μg/L which has been established by the WHO. Contamination sources are distributed over a large area from the Red River Delta in the north to the Mekong River Delta in the south, putting as many as ten million people at risk of adverse health effects. Levels of arsenic and iron in sediment are strongly correlated, which indicate that the presence of arsenic in groundwater results from the reduction of arsenic bound to iron oxyhydroxides. It is important to raise awareness of these issues among the Vietnamese public by disseminating information about the negative effects of contaminated drinking water, as well as carrying out long-term research projects to identify other sources of contamination and improving water treatment technology and water management capabilities.

Improving Private-Well Water Quality, North Carolina

MacDonald Gibson J, Pieper KJ. Strategies to Improve Private-Well Water Quality: A North Carolina Perspective. Environmental health perspectives. 2017 Jul 7;125(7):076001. doi: 10.1289/EHP890.

BACKGROUND: Evidence suggests that the 44.5 million U.S. residents drawing their drinking water from private wells face higher risks of waterborne contaminant exposure than those served by regulated community water supplies. Among U.S. states, North Carolina (N.C.) has the second-largest population relying on private wells, making it a useful microcosm to study challenges to maintaining private-well water quality.

OBJECTIVES: This paper summarizes recommendations from a two-day summit to identify options to improve drinking-water quality for N.C. residents served by private wells.

METHODS: The Research Triangle Environmental Health Collaborative invited 111 participants with knowledge of private-well water challenges to attend the Summit. Participants worked in small groups that focused on specific aspects and reconvened in plenary sessions to formulate consensus recommendations.

DISCUSSION: Summit participants highlighted four main barriers to ensuring safe water for residents currently relying on private wells: (1) a database of private well locations is unavailable; (2) racial disparities have perpetuated reliance on private wells in some urbanized areas; (3) many private-well users lack information or resources to monitor and maintain their wells; and (4) private-well support programs are fragmented and lack sufficient resources. The Summit produced 10 consensus recommendations for ways to overcome these barriers.

CONCLUSIONS: The Summit recommendations, if undertaken, could improve the health of North Carolinians facing elevated risks of exposure to waterborne contaminants because of their reliance on inadequately monitored and maintained private wells. Because many of the challenges in N.C. are common nationwide, these recommendations could serve as models for other states.

Microbial Contamination of Drinking Water Tubewells; Bangladesh

Dey NC, Parvez M, Dey D, Saha R, Ghose L, Barua MK, Islam A, Chowdhury MR. Microbial contamination of drinking water from risky tubewells situated in different hydrological regions of Bangladesh. Int J Hyg Environ Health. 2016 Dec 29. pii: S1438-4639(16)30270-X. doi: 10.1016/j.ijheh.2016.12.007.

This study, conducted in 40 selected upazilas covering four hydrological regions of Bangladesh, aimed at determining the risk of selected shallow tubewells (depth<30m) used for drinking purpose (n=26,229). This was based on WHO’s sanitary inspection guidelines and identifying the association of sanitary inspection indicators and risk scores with microbiological contamination of shallow tubewells. The main objective of the study was to observe the seasonal and regional differences of microbial contamination and finally reaching a conclusion about safe distance between tubewells and latrines by comparing the contamination of two tubewell categories (category-1: distance ≤10m from nearest latrine; n=80 and category 2: distances 11-20m from nearest latrine; n=80) in different geographical contexts. About 62% of sampled tubewells were at medium to high risk according to WHO’s sanitary inspection guidelines, while the situation was worst in south-west region. Microbiological contamination was significantly higher in sampled category-1 tubewells compared to category-2 tubewells, while the number of contaminated tubewells and level of contamination was higher during wet season. About 21% (CI95=12%-30%), 54% (CI95=43%-65%) and 58% (CI95=46%-69%) of water samples collected from category-1 tubewells were contaminated by E. coli, FC, and TC respectively during the wet season. The number of category-1 tubewells having E.coli was highest in the north-west (n=8) and north-central (n=4) region during wet season and dry season respectively, while the level of E.coli contamination in tubewell water (number of CFU/100ml of sample) was significantly higher in north-central region. However, the south-west region had the highest number of FC contaminated category-1 tubewells (n=16 & n=17; respectively during wet and dry season) and significantly a higher level of TC and FC in sampled Category-1 tubewells than north-west, north-central and south-east region, mainly during wet season. Multivariate regression analysis could identified some sanitary inspection indicators, such as tubewell within <10m of latrine, platform absent/broken, pollution source (i.e. household’s waste dumping point/poultry/dairy farm) within 10m of tubewell and unimproved sanitation facility which were significantly associated with presence of microbial contaminants in tubewell water (p<0.01). A tubewell with high risk level was associated with a higher chance of having FC and TC in tubewell water than a tubewell with a medium risk during wet season, but no such conclusion could be drawn in case of E.coli contamination. Construction of pit latrine in areas with high water table should be highly discouraged. Raised sealed pits or flush/pour flash to septic tank could be installed considering sanitary inspection criteria. Water should be treated before drinking.

Arsenic and Fluoride Co-occurrence, Northeast India

Kumar M, Das A, Das N, Goswami R, Singh UK. Co-occurrence perspective of arsenic and fluoride in the groundwater of Diphu, Assam, Northeastern India. Chemosphere 2016 Feb 19;150:227-238. doi: 10.1016/j.chemosphere.2016.02.019.

Considerable lacunae exists in As and F co-contamination investigation in the Brahmaputra and Gangetic floodplains. Therefore we selected Diphu a township in the Karbi Plateau rising from the Brahmaputra floodplains for evaluation of As and F co-occurrence, correlation with coexisting ions of the aquifer system and elucidation of potential processes for releasing As and F in the groundwater. Our initial appraisal used generic plots for identification of hydro geochemical processes and major water types. Subsequently, As and F co-occurrence with pH, depth, HCO3, SO42-, Ca2+ and Fe were probed for possible correlation followed by hierarchical cluster analyses to identify key processes for co-occurrence. Finally, saturation indices of groundwater minerals were calculated using MINTEQA2 to elucidate prospective As and F release into groundwater. Results indicate F and As presence in Ca-HCO3 rich water along with positive correlation between Ca2+ and F possibly due to limestone reserves in adjoining areas. Multivariate analyses suggest the presence of high concentrations of PO43-, and H4SiO4 either individually or in combination can enhance the mobility of both As and F and possibly abet conditions conducive for co-contamination of aquifers. Initial release of As and F from the parent rock seems driven by the anthropogenic activities while mobilization depends on chemical interactions and individual affinities of the elements. The results of speciation highlight further mobilization of As and F into the groundwater which in turn require regular attention for sustainable management of scarce water resource present in the area.