Analysis of the condition of karst springs included in the National Groundwater Monitoring Network

Approximately 20% of the monitored points in the National Groundwater Monitoring Network (NGMN) of Bulgaria are karst springs. The number of monitored karst springs is changing over time for various reasons and currently there are 33 springs monitored continuously and 53 on monthly basis. The monitoring points are distributed over 39 karst basins around the whole country. There are between 1 and 5 monitored springs per karst basin and no monitoring points in 23 karst basins. The present analysis includes the determination of some of the main statistical characteristics of karst springs and it is based on the monitoring data series. The obtained data allow us to make some conclusions of the nature of their water regime. Based on the analysis, some suggestions and recommendations are made with regard to improvements in the monitoring of karst springs in Bulgaria.

Molecular characterization of bacterial diversity in New Zealand groundwater

<p>Groundwater is a globally important natural resource and an integral part of the water supply in New Zealand. Due to high demand, the quality and availability of groundwater are both extensively monitored in New Zealand and globally, under State-of-the-Environment (SOE) monitoring programmes. SOE groundwater monitoring in New Zealand mainly evaluates hydrochemistry and until this thesis has largely overlooked the biotic component. Microbes including bacteria play a crucial role in ecosystem functioning by mediating biogeochemical processes in subsurface environments. Therefore, analysis of microbiological content will enable better evaluation of the health of groundwater ecosystems that is not fully reflected by chemical data alone. This project characterizes the bacterial diversity in New Zealand groundwater at national and regional scales using molecular methods and explores the underlying factors that shape the bacterial community structure. A simple molecular profiling tool, Terminal Restriction Fragment Length Polymorphism (T-RFLP) was used to determine community structure at local and national scales. The results revealed considerable diversity that was driven by groundwater chemistry. Roche 454-pyrosequencing was then used to obtain a deeper insight into New Zealand groundwater ecosystems, and showed that bacterial communities have many low abundance taxa and relatively few highly abundant species. In addition, microbial diversity is mainly related to the redox potential of the groundwater. But, despite this relationship, Pseudomonas spp. were the dominant genus at many sites even those with diverse chemistries and environmental factors. The final phase of the project set the platform to test whether these Pseudomonas spp. have acquired genetic material from other species via horizontal gene transfer (HGT) enabling them to adapt into a diverse range of habitats. A whole-genome sequencing approach (Illumina MiSeq platform) was used to develop six metagenomic databases as a resource to test this hypothesis. Initial results show some evidence for HGT and further investigations are underway. Overall, the knowledge generated across all phases of this project provides novel insights into New Zealand groundwater ecosystems and creates a scientific basis for the future inclusion of microbial status assessment criteria into regional and national groundwater monitoring programmes and related policies in New Zealand.</p>

Molecular characterization of bacterial diversity in New Zealand groundwater

<p>Groundwater is a globally important natural resource and an integral part of the water supply in New Zealand. Due to high demand, the quality and availability of groundwater are both extensively monitored in New Zealand and globally, under State-of-the-Environment (SOE) monitoring programmes. SOE groundwater monitoring in New Zealand mainly evaluates hydrochemistry and until this thesis has largely overlooked the biotic component. Microbes including bacteria play a crucial role in ecosystem functioning by mediating biogeochemical processes in subsurface environments. Therefore, analysis of microbiological content will enable better evaluation of the health of groundwater ecosystems that is not fully reflected by chemical data alone. This project characterizes the bacterial diversity in New Zealand groundwater at national and regional scales using molecular methods and explores the underlying factors that shape the bacterial community structure. A simple molecular profiling tool, Terminal Restriction Fragment Length Polymorphism (T-RFLP) was used to determine community structure at local and national scales. The results revealed considerable diversity that was driven by groundwater chemistry. Roche 454-pyrosequencing was then used to obtain a deeper insight into New Zealand groundwater ecosystems, and showed that bacterial communities have many low abundance taxa and relatively few highly abundant species. In addition, microbial diversity is mainly related to the redox potential of the groundwater. But, despite this relationship, Pseudomonas spp. were the dominant genus at many sites even those with diverse chemistries and environmental factors. The final phase of the project set the platform to test whether these Pseudomonas spp. have acquired genetic material from other species via horizontal gene transfer (HGT) enabling them to adapt into a diverse range of habitats. A whole-genome sequencing approach (Illumina MiSeq platform) was used to develop six metagenomic databases as a resource to test this hypothesis. Initial results show some evidence for HGT and further investigations are underway. Overall, the knowledge generated across all phases of this project provides novel insights into New Zealand groundwater ecosystems and creates a scientific basis for the future inclusion of microbial status assessment criteria into regional and national groundwater monitoring programmes and related policies in New Zealand.</p>

Baseline surface- and groundwater monitoring prior to an onshore shale gas operation in the Vale of Pickering, UK

A comprehensive programme of baseline groundwater hydrochemical monitoring has been carried out in connection with the proposed hydraulic fracturing of a 2 to 3 km deep Bowland Shale gas reservoir in borehole KM8 at Kirby Misperton, North Yorkshire, UK. The monitoring infrastructure encompassed: five on-site boreholes with hydraulically open intervals ranging from shallow weathered cover to a c. 200 m deep Corallian limestone aquifer, six off-site wells (hydraulically open in superficial materials and/or Kimmeridge Clay) and four surface water monitoring stations. Groundwater chemistry was high stratified with depth, ranging from slightly acidic, fresh, very hard Ca-HCO3-SO4 waters in shallow weathered cover, to brackish, calcium-depleted, highly alkaline waters in the Corallian aquifer. Dissolved methane was detected in most boreholes, with 10 µg/L being typical of shallow boreholes and around 50 mg/L in the Corallian. Low ethane concentrations and isotopic evidence suggest that the methane was predominantly microbial in origin (carboxylate fermentation at shallow depth, natural methanogenic CO2 reduction at greater depth). Elevated dissolved ethane (20-30 µg/L) was found in one well of intermediate depth, suggesting admixture of a possible thermogenic component, although this could be derived directly from the Kimmeridge Clay penetrated by the well.

Development of IoT Real-Time Groundwater Monitoring System

Internet of Things (IoT) Real-Time Groundwater Monitoring System is a system built to monitor groundwater extraction and consumption. Groundwater scarcity has become a major threat to the government especially water utility company. Water theft, inaccuracy meter reading & lock out access are some problems contributing to water scarcity. In this research, data obtained from the groundwater consumption using flow sensor will be sent to the server where all this data will be recorded for future analysing by respective authorities. The system has been tested thoroughly using of Long Range (LoRa) communication module together with Thingspeak cloud and mobile application. The results showed promising coverage with Line of Sight (LOS) is tested at 900m maximum while for Non-Line of Sight (NLOS) is at 600m. A very small standard deviation up to 4.93 was observed for received Signal Strength Indicator (RSSI) value for LOS and NLOS. Compared with the existing manual method, the proposed IoT system will water authority to monitor water consumption effectively through real time and better coverage.

Construction dewatering in reclaimed land in Hong Kong — a review of best practices

A sound understanding of groundwater engineering principles is a prerequisite for effective construction dewatering and the associated pumping tests. This paper makes practical recommendations to improve dewatering designs in reclaimed land in Hong Kong and the interpretation of groundwater monitoring data. The paper first introduces the reader to the hydrogeology of Hong Kong and its implications on dewatering. It then draws upon experiences in Hong Kong, reviewing and recommending best practices in groundwater monitoring, and the design of extraction and recharge wells.

Hydrogeochemical Evolution of an Aquifer Regulated by Pyrite Oxidation and Organic Sediments

Detailed full-scale groundwater monitoring was carried out over a period of nine years, sampling at selected points along the groundwater flow direction in its final stretch. This established the hydrogeochemical evolution along the flow of a natural system formed by a calcareous aquifer which discharges and then passes through a quaternary aquifer of lake origin which is rich in organic matter. This evolution is highly conditioned by the oxidation of pyrites that are abundant in both aquifers. In the first aquifer, one kilometre before the discharge location, oxidizing groundwater crosses a pyrite mineralization zone whose oxidation produces an important increase in sulphates and water denitrification over a short period of time. In the quaternary aquifer with peat sediments and pyrites, water experiences, over a small 500 m passage and residence time of between three and nine years, a complete reduction by way of pyrite oxidation, and a consequent increase in sulphates and the generation of hydrogen sulphuric acid. This is an example of an exceptional natural hydrogeological environment which provides guidance on hydrogeochemical processes such as denitrification.

Pilot-Scale Groundwater Monitoring Network for Earthquake Surveillance and Forecasting Research in Korea

Although there is skepticism about the likelihood of predictive success, research on the prediction of an earthquake through precursory changes in natural parameters, including groundwater, has continued for decades. One of the promising precursors is the changes in groundwater, i.e., the level and composition of groundwater, and the monitoring networks are currently operated to observe earthquake-related changes in several countries situated at the seismically active zone. In Korea, the seismic hazards had not been significantly considered for decades since the seismic activity was relatively low; however, the public demands on the management and prediction of earthquakes were raised by two moderate-size earthquakes which occurred in 2016 and 2017. Since then, a number of studies that were initiated in Korea, including this study to establish a pilot-scale groundwater-monitoring network, consisted of seven stations. The network is aimed at studying earthquake-related groundwater changes in the areas with relatively high potentials for earthquakes. Our study identified a potential precursory change in water levels at one particular station between 2018 and 2019. The observed data showed that most monitoring stations are sufficiently isolated from the diurnal natural/artificial activities and a potential precursory change of water level was observed at one station in 2018. However, to relate these abnormal changes to the earthquake, continuous monitoring and analysis are required as well as the aid of other precursors including seismicity and geodetic data.