Plain Aquifer Research Articles

Geospatial Data Assimilation and Mapping Groundwater Vulnerability in High Plains Aquifer Using DRASTIC Model

Geospatial Data Assimilation and Mapping Groundwater Vulnerability in High Plains Aquifer Using DRASTIC Model

Aquifer System, Recharge-Discharge Zone and Groundwater Basin Boundary Mapping to Support Open and Transparent Water Data, Case Study: Karangkobar Groundwater Basin

Sustainable groundwater management based on groundwater basin (GWB) must be equipped with comprehensive information including the characteristic of hydrogeology. This management method is very useful for governments to design some regulations, such as tax and conservation zone. Nowadays, not only the government but the public society can also have access to know this management. Open and transparent groundwater application needs sufficient data. Based on that issue, this research aims to provide the geological and hydrogeological conditions of GWB, define the aquifer configurations, and determine the groundwater recharge-discharge zones and the type of GWB boundary on Karangkobar GWB. The methods applied to the study are 1) mapping the geological and hydrogeological condition; 2) reconstruction of subsurface stratigraphic condition; and 3) overlay four parameters of the recharge-discharge zone. The Karangkobar GWB consists of the unconfined and confined aquifer of High Plain Aquifer, where the groundwater flows from north and east heading southward and westward. Seven boundary types bounded the Karangkobar GWB. The map can also support the open and transparent water data application system, it will also ease the party that will conduct an assessment to design regulation regarding the groundwater management.

Applicability of the dual isotopes δ15N and δ18O to identify nitrate in groundwater beneath irrigated cropland

Identification of the nitrate sources that adversely impact groundwater quality is a necessary first step in the control of this major worldwide pollutant. The impact of nitrate leachate from urea-ammonium nitrate (UAN) (50% urea-N, 25% ammonium-N, 25% nitrate-N) fertilizer, whose use has increased dramatically in the last three decades largely because it can be applied through sprinkler irrigation systems to corn in all growth stages, is investigated. The dual isotopes δ15NNO3 and δ18ONO3 were measured in groundwater samples from 39 irrigation wells in two intensively sprinkler-irrigated, corn-growing areas of Nebraska with nitrate-contaminated (N > 10 mg/L) groundwater and documented UAN use to ascertain whether nitrified ammonia and nitrate fertilizers can be distinguished in the High Plains aquifer. The areas, which are highly vulnerable to nitrate leaching and differ only in the composition and thickness of their unsaturated zones, are uniquely suited to provide scientific evidence of the feasibility of identifying nitrate fertilizer leachate in groundwater and thereby add significantly to the small body of existing and inconclusive data. The dual isotope method (DIM) results indicate that the nitrate contamination in 38 wells is mostly nitrified ammonium fertilizer. Most importantly, nitrate fertilizer from UAN was not identified isotopically in groundwater beneath almost all fields with documented heavy UAN use. This could be a potentially valuable finding for fertilizer management or it could convey limitations on the appropriateness of the DIM for nitrate fertilizer source identification in groundwater. Slightly enriched δ15NNO3 values in a few wells coincide with the practice of wintering cattle on corn stubble, which reportedly occurred more frequently in one focus area. The absence of natural soil-N leachates and denitrification in groundwater enabled an apparently reliable identification of manure leachates in both areas.

Factors affecting the occurrence of lead and manganese in untreated drinking water from Atlantic and Gulf Coastal Plain aquifers, eastern United States—Dissolved oxygen and pH framework for evaluating risk of elevated concentrations

Groundwater samples collected during 2012 and 2013 from public-supply wells screened in the Atlantic and Gulf Coastal Plain aquifers of the eastern and southeastern U.S. rarely contained lead or manganese concentrations that exceeded drinking-water limits, despite having corrosive characteristics. Data indicate that the occurrence of dissolved lead and manganese in sampled groundwater, prior to its distribution or treatment, was related to several explanatory factors including the presence of source minerals, hydrologic position along the flow path, water-rock interactions, and associated geochemical conditions such as pH and dissolved oxygen (DO) concentrations. Elevated concentrations of lead compared to health-based benchmarks were associated with groundwater that is acidic (pH ≤ 6.5), oxygenated (DO ≥ 2 mg/L), and closer to recharge zones (relatively young water). Elevated concentrations of manganese were associated with groundwater that is acidic to neutral (pH ≤ 7.5), has low DO (<2 mg/L), and further from recharge zones (relatively old). Under these geochemical conditions, minerals that could sequester lead or manganese tended to be undersaturated, and adsorption by hydrous ferric oxide was limited. Under neutral to alkaline pH conditions, precipitation of impure calcium carbonate or phosphate compounds containing traces of lead or manganese (solid solutions) could maintain low concentrations of the trace elements. Additionally, adsorption of lead or manganese cations by hydrous ferric oxides (HFO) could be another attenuating factor where conditions are oxidizing and dissolved inorganic carbon concentrations are relatively low. A DO/pH framework was developed as a screening tool for evaluating risk of elevated lead or manganese, based on the occurrence of elevated lead and manganese concentrations and the corresponding distributions of DO and pH in the Atlantic and Gulf Coastal Plain aquifers. Validation of the DO/pH framework was accomplished using an independent national dataset that showed consistent results for elevated lead (pH ≤ 6.5; DO ≥ 2 mg/L) and manganese (pH ≤ 7.5; DO < 2 mg/L).

The Role of Peer Effects in Natural Resource Appropriation – The Case of Groundwater

AbstractSpatially mediated peer effects are increasingly recognized as an important driver of technology adoption. In this paper, we isolate the role of peer effects from environmental factors in the acquisition of groundwater rights for agricultural irrigation in Kansas. We find strong evidence of peer effects influencing farmers’ decisions to adopt groundwater irrigation. Using a rich dataset on groundwater rights for the period 1943–2014 and a nearest neighbor peer group definition, we find that one additional neighbor adopting groundwater for irrigation increases groundwater adoption by an average of 0.25 percentage points. We also find that the average marginal effect of one additional peer is reduced by distance and diminishes as the total number of neighbors adopting groundwater increases. Using our model estimates to simulate a counterfactual without peer effects, we find that water rights appropriation stemming from peer effects accounted for about 11 million acre‐feet of extraction from the Kansas High Plains Aquifer. This amounts to about three years of typical annual extraction. Our results provide evidence that peer effects can “speed up” resource extraction and can help inform policy makers in designing exploitation control rules.

Time‐domain electromagnetic imaging of a clayey confining bed in a brackish environment: A case study in the Kairouan Plain Aquifer (Kelbia salt lake, Tunisia)

AbstractThe semi‐arid Plio‐Quaternary aquifer of the Kairouan Plain is located in the central part of Tunisia. In this region, the main form of human activity is extensive agriculture. The few lithological logs in this area indicate that the aquifer is divided into two groundwater reservoirs separated by a confining clay layer. In the shallower groundwater reservoir, the electrical conductivity of the water is close to 1,200 mS/m, that is, 3 to 4 times higher than that of the deeper aquifer, which is currently used for irrigation. Recently, an increase in salinity has been observed, which is producing significant difficulties with irrigation. In order to determine the geometry of the confining clay layer and assess the potential connectivity between both reservoirs, time‐domain electromagnetic (TDEM) and vertical electrical soundings surveys were carried out. In the extremely conductive environment (electrical resistivities &lt;10 Ωm) of the Sebkha Kelbia, the TDEM survey produced the first geophysical map of this near‐surface aquifer system.

Occurrence of metal-rich acidic groundwaters around the Mekong Delta (Vietnam): A phenomenon linked to well installation

Acidic groundwaters enriched with heavy metals are frequently observed in the coastal plain aquifers. The acidic pHs are observed even in the deep confined aquifers in southern Vietnam. This study geochemically explores the causes of these acidic groundwaters by investigating 41 groundwater samples, 4 soil samples and a 54 m long sediment core and the long-term monitoring data (4189 observations) obtained from 178 wells of the National Groundwater Monitoring Network for the South of Vietnam (NGMNS). The groundwater data show elevated Fe, Mn, Al, Pb, and Zn concentrations as the pH becomes acidic and suggest pyrite oxidation be the major cause for the groundwater acidification. This is further confirmed by pyrite framboids observed in the sediment or soil samples taken from the sites where strongly acidic groundwaters were observed. Results of leaching experiments using sediment and soil samples indicate that high metal concentrations in the acidic pH are associated with the increased metal solubility and mineral dissolution kinetics. The acidification of deep groundwaters is revealed to be associated with well installation, indicating the importance of proper well-installation techniques to protect water quality of deep confined aquifers.

Assessment of groundwater quality in a semiarid region of Northwestern Algeria using water quality index (WQI)

The present paper aims at determining the status and trends of groundwater quality of 12 aquifers situated in Northwestern Algeria, especially under conditions of last drought that has affected the region using water quality index (WQI) over a period of 4 years. Multivariate statistical methods have been used jointly with conventional graphical methods, to classify the samples according to plausible levels of groundwater evolution. The computed WQI values range from 67 to 588 and therefore can be categorized into four categories: “good water” to “water unsuitable for drinking.” Overall, 36% of groundwater sites sampled in the study area had good water quality, while 53% were poor. Unfortunately, 6% of the samples indicate “very poor water quality” and 5% represent water “unsuitable for drinking purposes.” Results show that the majority of groundwater of Tafna basin fell under good water quality. Groundwater of poor and medium quality characterizes the majority of the studied aquifers of Macta basin. The result showed that the water quality at monitoring station “Ain Skhouna” fell under good water quality (Chott Chergui aquifer). Results also show that groundwater of Coastal Oranais basin showed poor water quality, very poor at some monitoring stations of Mléta Plain aquifer. It has been demonstrated that the water of some aquifers has degraded under water scarcity conditions and will continue to degrade given the ongoing and projected development in the study area. The analysis reveals that the water of some aquifers needs treatment before it is used for human consumption. The influence of salt water on the some freshwater aquifers in the study area needs special attention in terms of monitoring and for sustainable management.

Climate change implications for irrigation and groundwater in the Republican River Basin, USA

This study investigates the influence of climate change on groundwater availability, and thereby, irrigation across political boundaries within the US High Plains aquifer. A regression model is developed to predict changes in irrigation according to predicted changes in precipitation and temperature from a downscaled dataset of 32 general circulation models (GCMs). Precipitation recharge changes are calculated with precipitation-recharge curves developed for prognostic representations of precipitation across the Nebraska-Colorado-Kansas area and within the Republican River Basin focal landscape. Irrigation-recharge changes are scaled with changes in irrigation. The groundwater responses to climate forcings are then simulated under new pumping and recharge rates using a MODFLOW groundwater flow model. Results show that groundwater pumping and recharge both will increase and that the effects of groundwater pumping will overshadow those from natural fluctuations. Groundwater levels will decline more in areas with irrigation-driven decreasing trends in the baseline. The methodologies and predictions of this study can inform long-term water planning and the design of management strategies that help avoid and resolve water-related conflicts, enabling irrigation sustainability.

In Situ and GRACE‐Based Groundwater Observations: Similarities, Discrepancies, and Evaluation in the High Plains Aquifer in Kansas

AbstractRelating Gravity Recovery and Climate Experiment (GRACE)‐derived terrestrial water storage anomaly (aTWS) variations to in situ groundwater data is important to understanding GRACE data utility. Here GRACE‐derived annual changes in aTWS (ΔTWS) from National Aeronautics and Space Administration's Jet Propulsion Laboratory and Goddard Space Flight Center are compared to annual changes in saturated groundwater volumes (ΔGW) in the High Plains aquifer (HPA) and overlying alluvial aquifers in Kansas. Regression analysis suggests that trends in ΔTWS are strongly related to trends in ΔGWalluvial and weakly related to trends in ΔGWHPA, although the magnitude of ΔTWS is much larger than ΔGWalluvial and is similar to ΔGWHPA. Unlike alluvial aquifers, a thick vadose zone overlies the HPA. Estimates of changes in vadose zone water content (ΔVZ) using GRACE products are similar in magnitude to annual variations in North American Land Data Assimilation soil moisture data, suggesting an unexpected dominance of ΔVZ in ΔTWS despite significant groundwater depletion. Results demonstrate that water storage changes in shallow alluvial aquifers, the root zone, the deep vadose zone, and the HPA itself are all significant in the HPA region of Kansas. Consequently, GRACE observations cannot, alone, be taken to reflect variations in saturated zone groundwater storage in the HPA, or other large, heavily used aquifers subject to substantial groundwater depletion, when deep unsaturated zones exist. GRACE can best provide guidance on regional aquifer storage changes where water storage changes in the vadose zone and perched or adjacent aquifers are well constrained.

Groundwater vulnerability assessment using the DRASTIC model under GIS platform in the Ajabshir Plain, southeast coast of Urmia Lake, Iran

The Ajabshir Plain aquifer is affected by lake water intrusion. The present study was conducted to investigate this plain, located in East Azerbaijan Province, Iran, in terms of vulnerability to contamination. Determining the most effective parameter in the aquifer vulnerability was the second aim of the study. The DRASTIC model was used to assess the intrinsic vulnerability of the aquifer applying seven hydrogeological parameters, including depth to water, net recharge, aquifer media, soil media, topography, impact of the vadose zone, and hydraulic conductivity. Depth to water map was provided using 26 boreholes. Twenty-seven drilling points were also used in generating aquifer media and impact of vadose zone maps. After providing and ranking all layers, they were multiplied by appropriate weights and overlaid to produce vulnerability map. The importance of each parameter in the vulnerability of the plain was evaluated through map removal and single-parameter sensitivity analyses. The DRASTIC map indicated that 13.4% area is under very low vulnerability, 55.4% under low vulnerability, 28.6% under moderate to low vulnerability, and 3% under moderate to high vulnerability. According to the DRASTIC map, only a small pocket in west is under the most vulnerable zone due to sand and gravel with high permeability in the vadose zone and low depth to water table. Sensitivity analysis proved that the DRASTIC index has the most sensitivity to remove depth to water table. The verification of the DRASTIC map using spatial distribution maps of total dissolved solids (TDS) and Cl−, and water table in 2002 and 2012 indicated that the generated DRASTIC map can be acceptable.

What Is the Use Value of Irrigation Water from the High Plains Aquifer?

AbstractThis study provides an estimate of the gross value of irrigation water from the U.S. High Plains Aquifer. We estimate a yield function for aggregated crop biomass production, based on county‐level observations for 1960–2007. This study found that irrigation increases total biomass yield in this region by an average of 51%. We estimate the average gross annual value of irrigation as of 2007 to be $196 per acre, for a total of about $3 billion across the aquifer. We also estimate that on average across the aquifer, exposure to 24 hours of temperatures above 33°C (one degree day) reduces biomass yield by 3%, with a value in 2007 of about $10 per acre.

Phase difference between groundwater storage changes and groundwater level fluctuations due to compaction of an aquifer-aquitard system

Drainage and deformation of intercalated confining layers due to internal stress change (discharge/recharge cycle) in an aquifer-aquitard system not only can have great effects on the groundwater storage (GWS), but also can cause unsynchronized water level (WL) fluctuations. The phase relationship between GWS and WL is crucial for the accuracy and attribution of GWS changes. We identify the dominating episodic components of GWS and WL through the Singular Spectrum Analysis (SSA) analysis and Harmonic analysis. First, we analyzed a generic aquifer-aquitard system using numerical simulations which showed that the dissipation of overpressure from the aquitard and flow from it is the inherent cause of a phase shift between the GWS and WL observations. Water released from confining layers with compaction time constant of zero (no-delay) to century time scale results in detected phase shift between total GWS and WL in the aquifer. Then, we analyzed the complex and varied phase relationship between GWS derived using the Gravity Recovery and Climate Experiment (GRACE) data and measured WL time series in the subsiding North China Plain (NCP) aquifer. The spatially varied phase relationship between GWS and measured WL is reasonably related to varied land subsidence development features and may be related with the compaction time constant and thickness of the confining layers. Results of the generic numerical model and the NCP observations suggest that elastic/inelastic response need to be considered in the interpretation and correction of GWS changes for a compacted aquifer-aquitard system.

Transience of the North American High Plains landscape and its impact on surface water.

Ecosystem diversity and human activity in dry climates depend not just on the magnitude of rainfall, but also on the landscape's ability to retain water. This is illustrated dramatically in the High Plains of North America, where despite the semi-arid modern and past climate, the hydrologic conditions are diverse. Large rivers sourced in the Rocky Mountains cut through elevated plains that exhibit limited river drainage but widespread surface water in the form of ephemeral (seasonal) playa lakes1, as well as extensive groundwater hosted in the High Plains aquifer of the Ogallala formations2. Here we present a model, with supporting evidence, which shows that the High Plains landscape is currently in a transient state, in which the landscape has bifurcated into an older region with an inefficient river network and a younger, more efficient, river channel network that is progressively cannibalizing the older region. The older landscape represents the remnants of the Ogallala sediments that once covered the entirety of the High Plains, forming depositional fans that buried the pre-existing river network and effectively 'repaved' the High Plains3-6. Today we are witnessing the establishment of a new river network that is dissecting the landscape, capturing channels and eroding these sediment fans. Through quantitative analysis of the geometry of the river network, we show how network reorganization has resulted in a distinctive pattern of erosion, whereby the largest rivers have incised the older surface, removed fan heads near the Rocky Mountains and eroded the fan toes, but left portions of the central fan surface and the Ogallala sediments largely intact. These preserved fan surfaces have poor surface water drainage, and thus retain ephemeral water for wetlands and groundwater recharge. Our findings suggest that the surface hydrology and associated ecosystems are transient features on million-year timescales, and reflect the mode of landscape evolution.

MODFLOW/MT3DMS Based Modeling Leachate Pollution Transfer in Solid Waste Disposal of Bahar Plain Deep Aquifer

Background and purpose: This paper presents a case study in simulation of process governing leachate occurrence and subsequent transport, and investigates its migration away from the landfill to control environmental adverse effects on a deep aquifer.Materials and Methods: The landfill examined in this study was an area of 240 ha and received 500 ton/day of solid waste generated from Hamedan and its surrounding including Bahar, and Jurghan. Based on the finite difference technique, leachate transport and penetration into the Hamedan plain aquifer was simulated exerting MODFLOW and MT3DMS codes in GMS Software.Results: It was concluded that landfill geological structure had the greatest influence on the transfer of urban solid waste leachate in traditional disposal sites. A low permeable conglomerate layer prohibited leachate migration to the main semi-confined aquifer. The results also indicated that urban solid waste leachate was only excited to migrate toward recharging waterways of aquifer by surface flows flooding as well as severe rainfalls.Conclusion: Geological structure of the landfill area had the greatest influence on the development of leachate pollution of municipal solid waste in traditional disposal sites. The spread of pollution to the deep aquifer near the waste disposal site was practically inhibited by an impermeable conglomerate layer in the municipal waste disposal.

Sustainability of aquifers supporting irrigated agriculture: a case study of the High Plains aquifer in Kansas

ABSTRACT The only means of moderating alarming depletion rates in many of the world’s major aquifers is to reduce pumping. We apply a new water-balance approach to assess the impact of pumping reductions in a portion of the High Plains aquifer in the United States. Although projected aquifer responses to pumping reductions vary, practically achievable reductions would have a large impact throughout the area. These findings demonstrate that modest pumping reductions could greatly enhance prospects for groundwater-supported irrigation in the High Plains aquifer and similar aquifers elsewhere.

Recognition of Regional Water Table Patterns for Estimating Recharge Rates in Shallow Aquifers.

We propose a new method for groundwater recharge rate estimation in regions with stream-aquifer interactions, at a linear scale on the order of 10km and more. The method is based on visual identification and quantification of classically recognized water table contour patterns. Simple quantitative analysis of these patterns can be done manually from measurements on a map, or from more complex GIS data extraction and curve fitting. Recharge rate is then estimated from the groundwater table contour parameters, streambed gradients, and aquifer transmissivity using an analytical model for groundwater flow between parallel perennial streams. Recharge estimates were obtained in three regions (areas of 1500, 2200, and 3300 km2 ) using available water table maps produced by different methods at different times in the area of High Plains Aquifer in Nebraska. One region is located in the largely undeveloped Nebraska Sand Hills area, while the other two regions are located at a transition zone from Sand Hills to loess-covered area and include areas where groundwater is used for irrigation. Obtained recharge rates are consistent with other independent estimates. The approach is useful and robust diagnostic tool for preliminary estimates of recharge rates, evaluation of the quality of groundwater table maps, identification of priority areas for further aquifer characterization and expansion of groundwater monitoring networks prior to using more detailed methods.

Application of Multi-Isotopes and Geochemical Modeling for Delineating Recharge and Salinization Sources in Dahab Basin Aquifers (South Sinai, Egypt)

The Dahab watershed comprises three aquifers; the alluvial Quaternary, the Early Cambrian sandstone, and the fractured Pre-Cambrian basement aquifers. The Dahab watershed is located in the southeastern part of the arid Sinai Peninsula, where low precipitation and groundwater over-exploitation deteriorate the groundwater quality in the alluvial coastal plain aquifer located downstream. Multi-isotopes including δ18O and δ2H, 87Sr/86Sr, δ81Br and δ11B coupled with groundwater geochemistry were utilized to assess the recharge source(s), water-rock interaction, and seawater mixing to aid sustainable groundwater management strategies. Br and Cl concentrations, used to measure groundwater salinity, were low in the upstream groundwater, while higher concentrations were observed in the deep drilled wells located downstream, in the main well field. The δ18O and δ2H isotopes were depleted in the upstream aquifers, but enriched in the shallow coastal aquifer, indicating slight evaporation and seawater intrusion. Higher mean values of 87Sr/86Sr and δ81Br were observed in the fresh groundwater from high in the watershed (87Sr/86Sr = 0.707716 and δ81Br = +2.05‰), while lower mean values were observed in the saline groundwater located downstream in the main well field (87Sr/86Sr = 0.706631 and δ81Br = +0.11‰). The cumulative mass balance mixing curves and the geochemical NETPATH model confirm the change of groundwater quality from the upper to lower watershed caused by the leaching and evaporation processes, as well as mixing with seawater. The corrected 14C age dating and stable isotopes show that the Quaternary and Pre-Cambrian basement aquifers contain modern groundwater, while the Early Cambrian aquifer holds paleo-groundwater, which has received considerable recharge from recent precipitation. The mixing ratiosin the Quaternary coastal aquifer range between 5% and 13% seawater to 95% and 87% fresh groundwater, respectively. These results indicate that future groundwater withdrawal must be well managed in order to limit further salinization. Groundwater withdrawal from the Quaternary coastal aquifer must be below the natural average recharge in order to be sustainable.

Groundwater Withdrawals Under Drought: Reconciling GRACE and Land Surface Models in the United States High Plains Aquifer

AbstractAdvanced Land Surface Models (LSM) offer a powerful tool for studying hydrological variability. Highly managed systems, however, present a challenge for these models, which typically have simplified or incomplete representations of human water use. Here we examine recent groundwater declines in the US High Plains Aquifer (HPA), a region that is heavily utilized for irrigation and that is also affected by episodic drought. To understand observed decline in groundwater and terrestrial water storage during a recent multiyear drought, we modify the Noah‐MP LSM to include a groundwater irrigation scheme. To account for seasonal and interannual variability in active irrigated area, we apply a monthly time‐varying greenness vegetation fraction (GVF) data set within the model. A set of five experiments were performed to study the impact of groundwater irrigation on the simulated hydrological cycle of the HPA and to assess the importance of time‐varying GVF when simulating drought conditions. The results show that including the groundwater irrigation scheme improves model agreement with ALEXI ET data, mascon‐based GRACE TWS data, and depth‐to‐groundwater measurements in the southern HPA, including Texas and Kansas, and that accounting for time‐varying GVF is important for model realism under drought. Results for the HPA in Nebraska are mixed, likely due to the model's weaknesses in representing subsurface hydrology in this region. This study highlights the value of GRACE data sets for model evaluation and development and the potential to advance the dynamic representations of the interactions between human water use and the hydrological cycle.

Toward an adaptive monitoring design for leakage risk – Closing the loop of monitoring and modeling

Monitoring is a key component of risk management at geologic carbon storage (GCS) sites, serving both to help operators understand and manage site performance, and to assure the public and other stakeholders that effective containment is maintained and impacts avoided. Potential leakage of CO2 and/or brine through wellbores, faults, and fractures to potable groundwater resources is a primary risk concern at onshore GCS sites. In this paper, we present an adaptive methodology for leakage risk-based monitoring design. The methodology uses a risk event tree to predict the likelihood of leakage occurrence, with detection probabilities of risk events estimated for multiple monitoring plans. The overall detection probability of a proposed monitoring plan incorporates baseline data, stochastically simulated leakage events, and the likelihood that a set of technologies will detect the changes in baseline conditions induced by the simulated leakage events. The adaptive monitoring design methodology is demonstrated with a representative case study of CO2 and brine leaking from a well to a potable groundwater aquifer using simulated data at the High Plains aquifer in the United States. Groundwater quality parameters, pH, total dissolved solids and benzene concentrations, were used to calculate the corresponding detection probabilities of conventional groundwater sampling and fixed sensor monitoring for selected leakage scenarios. The overall detection probability considering all monitoring information was then calculated to evaluate proposed monitoring plan designs. Finally, a simple optimization problem to maximize detection probability with constrained monitoring resources was presented as an application example to close the loop of monitoring and modeling.