Collector Wells Research Articles

Nutrient release in drainage discharge from organic soils under two different agricultural water management systems

AbstractThe release of available nitrogen (N) and phosphorus (P) from agricultural tile drainage contributes to eutrophication in water bodies. To mitigate the harmful impact of nutrient release, drainage water management (DWM) has been proposed as a beneficial management practice that will limit N and P in tile drainage discharge. This study, conducted in the organic soils of the Holland Marsh, Ontario, assessed the nutrient water quality for 2 years (2015–2016) under DWM systems: controlled drainage (CD) comprising a series of stackable gates to manually control the water table level; and pumped drainage (PD) which uses a submersible pump within a collector well that discharges effluent when activated. The latter is the common method of field drainage in the Holland Marsh, however, there is limited comparable research for either DWM system. The data were separated into growing and fallow seasons as well as winter, spring, and summer seasons for trend analysis (winter: October–February; spring: March–May; summer: June–September). The nitrate (NO3‐N) concentrations, under CD, were found to be on average higher during the winter season (7.64 mg L−1) compared to the growing season (3.76 mg L−1). Furthermore, total N concentrations are positively correlated to discharge (R > 0.55). The average total P concentration increased during the summer period following fertilization; however, there was no correlation between P and drainage discharge throughout the duration of the study. The P concentrations depended more on nutrient inputs, rather than the discharge under CD. The log regression statistical relationship showed significant differences in nutrient levels compared to the mean at both sites, however, greater differences were found under CD. Under PD, the NO3‐N concentrations showed significant seasonal trends between the spring and winter (Pr > t: 0.0061) and summer (Pr > t: <0.0001). Overall, both CD and PD can reduce the amount of tile drain discharge, but the concentrations of N and P are not significantly reduced.

Behavior of chlorpyrifos and 3,5,6-trichloro-2-pyridinol (TCP) in a sodium-dodecyl sulphate-electrokinetic soil washing system

Chlorpyrifos (CPF) is widely used around the world as an insecticide to control various insect pests. Numerous studies have shown that CPF and its main metabolite, 3,5,6-trichloropyridinol (TCP) are potential contaminants of soils and water resources. In this work an electro-kinetic soil washing treatment with alternating polarity (EKSW-AP) using the anionic surfactant SDS (4 times CMC) in the washing solution was studied as a possible strategy for CPF remediation in soils. The experiments were performed in two types of soils applying an electric field between the electrodes of 1 V cm−1 during 15 days of operation. The main results of this work showed that SDS does not improve the possibility of mobilization of CPF and TCP in the EKSW-AP treatment, due to the low remaining concentration after its adsorption on soils. In the reference systems, without current application, the recovery of CPF was close to 100% of the added mass whereas in the EKSW-AP systems recoveries reached values near to 80%. Kinetic studies performed in untreated soils revealed only the formation of TCP without any other degradation product. Therefore, EKSW-AP process likely favored the degradation of both compounds CPF and TCP, with the formation of another more polar by-product that was obtained in the collector wells. The results of this study showed that the EKSW-AP with the application of SDS does not significantly alter the physicochemical properties of the soils.

An Assessment of the Effectiveness of Riverbank Filtration in a Sewage Plant Effluent-Impacted River Using a Full-Scale Horizontal Well

From 2014 to 2020, a full-scale horizontal well was operated to investigate the performance of full-scale riverbank filtration (RBF) in the Nakdong River in Korea, which is significantly impacted by the effluents from sewage treatment plants. In this study, an individual lateral full-scale horizontal collector well was investigated for the first time in Korea, and its performance was determined based on the turbidity and levels of iron, total nitrogen, dissolved organic matter, and four selected trace organic contaminants (TrOCs) (tebuconazole, hexaconazole, iprobenfos, and isoprothiolane) in the RBF and Nakdong River. The turbidity of the river was high with an average of 10.8 NTU, while that of the riverbank filtrate was 0.5 NTU or less on average. The average dissolved organic carbon (DOC) concentrations were 2.5 mg/L in the river water and 1.4 mg/L in the riverbank filtrate, which indicated a 44% reduction in DOC content during the RBF. Out of the 10 laterals, 8 laterals exhibited similar levels of iron, manganese, total nitrogen, DOC, and total hardness, electrical conductivity, and turbidity. The characteristics of the remaining two laterals were different. Because the groundwater inflow was relatively low (<10%), the laterals were contaminated by agricultural land use before the installation of the RBF. This is the first study to report changes in water quality according to individual laterals in a river affected by wastewater effluents. The filtration unit exhibited more than 90% removal rates for tebuconazole and hexaconazole. However, the removal rate for iprobenfos was approximately 77%, while that for isoprothiolane was 46%. The four selected TrOCs in this study were not detected in the groundwater. We found that some organic micropollutants were effectively removed by the RBF.

Review: Horizontal, directionally drilled and radial collector wells

Horizontal wells play an often overlooked role in hydrogeology and aquifer remediation but can be an interesting option for many applications. This study reviews the constructional and hydraulic aspects that distinguish them from vertical wells. Flow patterns towards them are much more complicated than those for vertical wells, which makes their mathematical treatment more demanding. However, at some distance, the drawdown fields of both well types become practically identical, allowing simplified models to be used. Due to lower drawdowns, the yield of a horizontal well is usually higher than that of a vertical well, especially in thin aquifers of lower permeability, where they can replace several of the latter. The lower drawdown, which results in lower energy demand and slower ageing, and the centralized construction of horizontal wells can lead to lower operational costs, which can make them an economically feasible option.

Analytically Supported Numerical Modeling of Horizontal and Radial Collector Wells

AbstractRiverbank filtration (RBF) is widely used in drinking water production all over the world. The horizontal and radial collector wells are among the most important water production facilities...

Application of collecter well to replace the conventional method in the northern mountainous area

The solution of using a collector well was investigated to take additional water, overcome the weaknesses of the conventional weir that are prone to sediment accumulation intake structures of a weir, especially at the location where weir is not needed. The solution was considered using a laboratory model at Hydraulic Construction Institute - Vietnam Academy for Water Resources. The results of model research and construction of a pilot project in Muong Lan commune, Muong Ang district, Dien Bien province show that collector well can collect water over 31 l/s ensuring water supply for more than 20 ha of rice field.

Groundwater Productivity and Rehabilitation of Radial Collector Wells for Agriculture near Okseong Underground Dam

When a radial collector well is installed and operated for agricultural purposes, negative impacts may be observed over time due to the clogging of horizontal arms, such as reduced groundwater discharge and water quality deterioration. When radial collector well No. 2 was rehabilitated using the high-pressure impulse generation technique, the specific capacity and transmissivity were increased by 43.1 and 100.6%, respectively. In contrast, according to air surging, the specific capacity and transmissivity increased by 33.8 and 85.8%, respectively, compared to the initial rate before rehabilitation. During the operation of radial collector wells since construction, the time of well rehabilitation can be effectively determined by continuously monitoring the groundwater level and pumping rate of the radial collector wells, thereby preventing a decrease in productivity.

Horizontal and radial collector wells: simple tools for a complex problem

The capture of groundwater by horizontal wells (HWs) is an old but often overlooked technique. Practically all modeling techniques available in groundwater hydrology have been applied to HWs. This work compares analytical models with field data and investigates the influence of nonuniform screen inflow. The usefulness of a vertical well approximation is studied. A new MATLAB application, HORI, is presented for common analytical models. Analytical methods are found to reproduce drawdown around two radial collector wells (RCWs). Beyond the direct vicinity of the caisson, in particular, drawdown around an RCW can be approximated with a vertical well model.

West Moesian uplifted hydrogeological system

A comprehensive analysis of the hydrogeological conditions in the westernmost part of the Bulgarian Danube Plain is presented. During the Neogene and Quaternary period this area is subjected to continuous uplift. As a result, river valleys are deeply incised into the terrain and all shallow aquifers are well drained in the hydrological network. This process determines the specific regime and dynamics of the groundwater, characteristic of the identified West Moesian uplifted hydrogeological system. The Quaternary aquifer is the most abundant in the system. It is formed in four riparian lowlands – two along the Timok River (Bregovska and Baley-Kudelin) and two along the Danube River (Novoselska and Vidin Lowlands) (Figs 1, 7, 8). The hydraulic properties of the aquifer are very good: Transmissivity T = 800-1000 m2/d and hydraulic conductivity K = 60-80 m/d. Several Ranney water collector wells extracting up to 140 L/s have been built in the Vidin lowland. Potential groundwater resources in this lowland are estimated at about 14 m3/s, with 13 m3/s being infiltrated from the Danube River. Second in importance in the hydrogeological system is the Sarmatian aquifer. It consists of two layers: upper – limestone and lower – sandy limestone (Figs 2 and 3). The waters are used for local water supply by capturing karst springs. The results of monitoring observations on the chemical composition of groundwater during the period 1980-1991 are presented in diagrams (Figs 4, 5, 6, 9, 11, 12, 13). Groundwater, being the only water source in the area, must be carefully protected from industrial and agricultural pollution.

Hydrodynamic analysis of radial collector well ageing at Belgrade well field

The origin and effect of hydraulic resistances on the rate of ageing of radial collector wells are identified through numerical hydrodynamic analysis. The research includes hydrodynamic modeling of one such well with new laterals at Belgrade well field. The performance of the laterals is aggravated by rapid ageing. The change in the hydraulic parameters of the laterals during the first decade of operation is analyzed through simulations of the groundwater regime with realistically specified geometries and hydraulics of the laterals. Contrary to previous investigations, two genetically different types of clogging were identified. The initial hydraulic resistances are a result of colmation due to the gravel pack grain-sizes and screen slot sizes being mismatched with the sand and gravel sediments of the aquifer deposited at the depth of the laterals. Colmation affects the hydraulic performance of the laterals. Well ageing is aggravated by incrustation, caused by high iron concentrations in the captured groundwater. The research highlights a strong correlation between increasing resistances at the laterals, on account of iron precipitation, and groundwater entrance velocities at the laterals. It is possible to differentiate between colmation and incrustation and accurately define the increase in resistances at the laterals by specifying known thicknesses of the near-lateral screen zones and quantifying hydraulic conductivities of those zones. MODFLOW–USG code and Connected Linear Network Process package are recommended for simulating laterals and defining real rather than hydraulically equivalent characteristics of the laterals, as an approach to hydrodynamic investigations relating to radial collector wells.

Feasibility Study of Riverbed Filtration Technique at Sungai Kampar Perak by using Numerical Modelling

Population growth will result in the increase of water supply demand. Riverbed filtration or radial collector well technique is one of the options for increasing the water supply. Drainage Package of Visual MODFLOW was used for the riverbed filtration modelling. The modelling aimed to identify the optimum pumping rates withdrawal in order to fulfill Lembaga Air Perak requirement for additional water supply. Installation of radial collector wells in the depth of 10-12 m aquifer thickness at Sungai Kampar Perak would increase the supply of clean water for future water demand. The design of riverbed filtration technique consists of 4 m radius of collector well with depth of 10.54 m and five radials wells with 40 m length across the riverbed. Transient condition of the groundwater flow modelling result showed that the optimum pumping rate can meet the water supply requirements of about 35 MLD (35000 m3/day).

Determination of Riverbed Filtration Potential as Water Supply Source using Geoelectrical Method

River bank filtration (RBF) is the influx of river water to the aquifer induced by a hydraulic gradient. Collector wells located on the banks in a certain distance from the river creates a pressure head difference between the river and aquifer, which induces the water from the river to flow downward through the porous media into the pumping wells. By applying this system of drinking water extraction, two different water resources are used where surface water from the river percolates towards the well; and groundwater of the surrounding aquifer is utilized. A study on the potential of RBF near the existing intake of Lembaga Air Perak at Sg Kampar was undertaken. Geophysical survey using resistivity traverses was made with 5 lines each on the right and left bank of the river. Three lines perpendicular and 2 lines parallel to Sg Kampar were investigated for possible water potential for RBF. The Wenner-Schlumberger configuration was chosen based on space provided in flatten areas and the depth of penetration interest in order to identify the presence of groundwater, stream-aquifer interaction and subsurface lithologies. Results from 2-dimensional profiles indicated that: (a) permeable soil saturated with water (possible groundwater and terrestrial sediments material) showed the resistivity value ranges of 0-150 ohm.m (b) semi permeable soil and weathered rock showed the resistivity value ranges of 200-1000 ohm.m and (c) impermeable soil and rock (unsaturated zone) showed the resistivity value ranges of 1000-7000 ohm.m.

Riverbank Filtration for the Water Supply on the Nakdong River, South Korea

A field study was carried out to investigate the feasibility of a riverbank filtration site using two vertical wells on the Nakdong River, South Korea. The riverbank filtration site was designed to have eleven horizontal collector wells in order to supply 280,000 m3/day. This field study provided more insight into the fate of the dissolved organic matter’s characteristics during soil passage. The vertical production wells (PWs) were located in different aquifer materials (PW-Sand and PW-Gravel) in order to determine the depth of the laterals for the horizontal collector wells. The turbidity of the riverbank filtrates from the PW-Sand (0.9 NTU) and PW-Gravel (0.7 NTU) was less than 1 NTU, which was the target turbidity of the riverbank filtrate in this study. The iron concentrations were 18.1 ± 0.8 and 25.9 ± 1.3 mg/L for PW-Sand and PW-Gravel respectively, and were higher than those of the land-side groundwater. The biodegradable organic matter-determined biochemical oxygen demand in the river water was reduced by more than 40% during soil passage, indicating that less microbial growth in the riverbank filtrate could be possible. Moreover, the influence of the pumping rates of the vertical wells on the removal of dissolved organic matter and the turbidity was not significant.

Flow Analysis through Collector Well Laterals: A Case Study from Sonoma County Water Agency, California

The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity < 0.305 m min−1 and axial flow velocity of lateral screens < 1.524 m s−1).

Determining Optimum Pumping Rates of Groundwater in Ttansum Island Related to Riverbank Filtration

Riverbank Filtration (RBF) is a kind of indirect artificial recharge method and is useful in obtaining higher-quality source water than surface water when procuring municipal water. This study evaluated optimal riverbank filtered water and the productivity of the radial collector wells on Ttansum Island in the area downstream of the Nakdong River, where Gimhae City is constructing a municipal water plant for the purpose of acquiring high-quality water. The RBF wells are planned to provide water to the citizens of Gimhae City through municipal water works. Groundwater flow modeling was performed with the following four scenarios: (a) 9 radial collector wells, (b) 10 radial collector wells, (c) 10 radial collector wells and two additional vertical wells, and (d) 12 radial collector wells. This study can be useful in determineing the optimum production rate of bank filtrated water not only in this study area but also in other places in Korea.

Comparison of the Prediction Methods for Production Rate of Collector Well in Riverbank Filtration

In this study, the Milojevic formula, the Hantush formula, and the numerical method, which are the three different methods used to predict the production rate of collector wells in riverbank filtration, were compared. Given a collector well placed in a hypothetical geologic formation, the production rate of the collector predicted by each method was as follows: 5,972 m3/day by the Milojevic formula, 5,286 m3/day by the Hantush formula, and 6,600 m3 /day by the numerical method. From these results, the Hantush formula appears to make the safest prediction. However, the Milojevic formula and the Hantush formula cannot take into account the clogging of riverbed which is inevitable in riverbank filtration. Therefore, for now the best method to apply in a collector well design in riverbank filtration is the numerical method with clogging layer included. Key words: Riverbank Filtration, Production Rate, Hantush, Milojevic, Numerical Method

A new approach to the definition of design criteria for radial collector wells in anoxic settings

The outcomes of a study on groundwater flow from a river to a radial collector well are presented in the paper. The considered well, RB-16, is part of a groundwater source that provides water supply to Belgrade (Serbia). The source relies on the alluvial aquifer of the Sava River. The groundwater is mildly anoxic (Eh ~ 125 mV, Fe2+ = 0.46 mg/L, NO3 ~ 0.24 mgN/L, O2 ~ 0.1 mg/L). The paper is specific in the sense that it presents a novel approach to the definition of water well susceptibility to iron incrustation in an anoxic alluvial setting. Maximum permissible screen entrance velocities, as well as the structural characteristics of the horizontal screens and the radial collector well itself, are determined based on correlations established between the rate of well incrustation, redox potential, iron concentration in groundwater, and screen entrance velocities. One of the criteria is that the hydraulic resistances, caused by the precipitation of iron on the horizontal screens, are being lower than specified. The correlations between maximum permissible screen entrance velocities (the velocities that still allow a lower-than-specified increase in local hydraulic resistances at the entrance to the screens) and biochemical indicators (Eh, Fe2+) were taken from previous papers by the same authors and their associates. Original software was used for hydraulic analysis of the potential capacity of the location of well RB-16. The software supports 3D analysis, including boundary conditions, and was adapted for this particular purpose.

한국의 농업용 방사상 집수정 현황 및 지속가능성

한국의 농업용 방사상 집수정 현황 및 지속가능성

Hydraulic characterization of laterals as applied to selected radial collector wells at Belgrade groundwater source

The paper examines the possibility of hydraulic characterization of radial well laterals in a manner that does not require prior hydrodynamic analysis by simulating groundwater extraction conditions on a numerical model. The first step of the proposed approach is to assess the groundwater level regime formed in the capture zone when the well is operating, which is indicative of the functional condition of the laterals and the aquifer potential in terms of groundwater availability. Then the efficiency of the laterals is examined through the hydraulic function of the skin zone, depending on its filtration properties. An expression for groundwater flow from the aquifer to the laterals (commonly used to simulate laterals on a hydrodynamic model) is employed to define representative values of the conductance coefficient of the skin zone (as an indicator of colmation), and then applied to several wells at Belgrade Groundwater Source. The present research shows that a conductance coefficient of [Ks/ds]=1.0?10-4 s-1 can be considered as the threshold value in relation to which the effects of colmation of well laterals are exhibited, which is consistent with the results reported by researchers who studied the effect of skin zone conductance on the occurrence and nature of the so-called early drawdown at radial collector wells. In addition to gaining insight into the present condition of the laterals, the proposed approach can be used to study the progress of colmation at different points in time and to quantify the effectiveness of regeneration of laterals.

Characteristic groundwater level regimes in the capture zones of radial collector wells and importance of identification (Case study of Belgrade Groundwater Source)

Assessment of the operating modes of radial collector wells reveals that the pumping levels in the well caissons are very low relative to the depth/elevation of the laterals, which is a common occurrence at Belgrade Groundwater Source. As a result, well discharge capacities vary over a broad range and groundwater levels in the capture zones differ even when the rate of discharge is the same. Five characteristic groundwater level regimes are identified and their origin is analyzed using representative wells as examples. The scope and type of background information needed to identify the groundwater level regime are presented and an interpretation approach is proposed for preliminary assessment of the aquifer potential at the well site for providing the needed amount of groundwater.