Drainage Discharge Research Articles

Feasibility of Predicting Subsurface Drainage Discharge With DRAINMOD Parameterized by Uncalibrated SURRGO Soil Properties and ROSETTA3

Feasibility of Predicting Subsurface Drainage Discharge With DRAINMOD Parameterized by Uncalibrated SURRGO Soil Properties and ROSETTA3

Reduction of Nitrate Leaching and Threats to Surface Water Under Conservation Tillage

Highlights Conservation agriculture practice (NT) improved soil organic matter, a principal indicator of soil health, soil health score (SHS) and CO2 respiration, and other soil physical and chemical properties vs. conventional till (CT) practice. Conservation agriculture practice (NT) promoted soil health functions under sufficient precipitation distribution and ample temperature conditions and aided the soil's retention ability to resist nitrate leaching and loads in subsurface drainage discharge systems. Uneven weather conditions, drought, and other variable agronomic practices rendered soil conditions unfavorable to retain nitrate and induced adverse effects by increasing the nitrate leaching and loads in NT vs. CT. The limited experiment period presented significant challenges for the evaluation and synthesizing of soil health motivations and barriers in the NT vs. CT. Abstract. An edge-of-field subsurface drainage discharge system removes excess subsurface water from agricultural fields to improve the conditions of the soil system making them favorable for plant growth. Conversely, edge-of-fields can increase the nitrate (NO3 -) offsite movement to surface water bodies, which ultimately impacts water quality. In St. Johns, MI. Two on-farm large areas were initiated in 2013 for conservation (NT) and conventional till (CT) practices, of which two microscale fields, an area of 4 acres for each, were delineated in 2019 for NT and CT practices under a corn/soybean crop rotation. NT and CT fields were monitored and evaluated through full water years (WYs) 2019-2022. The objective was to use an innovative approach in coupling edge-of-field with soil health assessments to learn how improved soil health functions are influencing nitrate leaching and loads. NT practice enhanced SOM, other physical properties, and soil health parameters, promoting soil health functions compared to CT practice under conditions of adequate precipitation and favorable temperatures. Additionally, it improved the soil's ability to retain and resist nitrate loads in the 2020 water year, with reductions of 9.6 and 18.3 kg/ha, respectively. In 2021, WY nitrate loads reported nearly an equal value in NT vs. CT (4.8 and 4.4 kg/ha, respectively). Factors of uneven weather conditions and drought, variable agronomic practices, and residual nitrogen after corn, rendered soil conditions unfavorable to retain nitrate and induced adverse effects by increasing the nitrate leaching and loads in NT vs CT in 2022 WY (8.1 and 5.8 kg/h, respectively). Therefore, the limited evaluation period (2019-2022 WYs) presented significant challenges and revealed no affirmative evidence that the improved soil health functions under NT reduced the nitrate leaching loads in all WYs of this research. Further research is needed to prove the impact of NT on improving soil health functions to sustainably reduce nitrate leaching and loads in edge-of-fields. Keywords: Conservation no-till (NT), Conventional till (CT), Nitrate load, Soil health functions, Subsurface drainage discharge, Water quality.

Utilizing rapid bioassessment protocols to evaluate impacts of abandoned mine drainage discharges on a receiving stream

Utilizing rapid bioassessment protocols to evaluate impacts of abandoned mine drainage discharges on a receiving stream

Application of alternative organic wetland media for acid mine drainage treatment: Insights on reformations of microbial community structure

Acid mine drainage (AMD) discharge, particularly from the North Eastern Coalfield (NEC), Assam, has been a major persistent ecological threat. A lab-scale constructed wetland (CW) deriving organic wastes as the wetland media was implemented to treat high acidity (724 mg L–1 as CaCO3) AMD loaded with sulfate (1000–1300 mg L–1). Metal contents in mine wastewater comprised iron, aluminium, manganese, zinc, cobalt, nickel and chromium as 104, 25, 6.2, 5.1, 1.1, 1.1 and 1.1 mg L–1, respectively. CW operated continuously at a hydraulic loading rate (HLR) of 0.03 m3 m–2 d–1 for 282 days. Effluent water quality was monitored, and resulting shifts in microbial diversity were identified. Results demonstrated 771 mg L–1 (as CaCO3) alkalinity in effluent and metal removal (87–100%), except Co and Mn, which surpassed effluent discharge criteria. Further, the high-throughput sequencing results revealed significant reformations in bacterial assemblages throughout the operational period. Proteobacteria (45%) and Bacteroidetes (26%) represented the major bacterial groups at the start-up of CW, which later declined due to the elimination of aerobic strains under anaerobic conditions. Additionally, methanogenic archaea suppressed greatly due to the competition from sulfate and iron-reducers. An increase in the relative abundances of key functional bacteria (Firmicutes, Bacteroidetes, Actinobacteria and Acidobacteria) in the treatment phase indicated stable operation. Sulfate reduction (62%) was partial, evidenced by the prominence of sulfate-reducing bacteria (SRB) (Thermodesulfobium, Syntrophobacter, Desulfomonile and Desulfovibrio). This study offers insights into the microbial dynamics within an organic-media-amended CW, which directly influences AMD treatment.

Influence of different axis-translation techniques using ceramic disks/microporous membrane filters on mechanical/hydraulic behavior of unsaturated soil

Element tests, such as water retention tests and triaxial tests, are efficient and widely used methods for investigating the elementary hydro-mechanical behavior of unsaturated soil. In recent research, discrepancies observed in unsaturated test results using axis-translation techniques (ATTs) with ceramic disks and microporous membrane filters (MM filters) have indicated that misunderstandings might be hiding behind the perceived elementary behavior seen in element tests. In this study, triaxial tests with ceramic disks and MM filters were firstly conducted on specimens of unsaturated completely decomposed granite sand, referred to as Masado in Japan, to compare the influence of different techniques on the test results. Then a soil–water-air coupled finite element-finite difference (FE-FD) method, based on a newly proposed unsaturated/saturated constitutive model coupled with a deformation-dependent water retention curve (WRC), was utilized to simulate triaxial tests as boundary value problems (BVPs) because of the non-uniform deformation of the specimens. Drained/vented triaxial tests showed that the stress–strain relation of Masado is basically the same regardless of the applied technique, while the amount of drainage discharge and degree of saturation during the shearing stage are quite different. The calculated average stress–strain relation basically reproduced a tendency similar to that of the tests. It was also shown from the calculation that the ATT with ceramic disks or MM filters significantly influences the distributions of saturation and stress within the specimens during shearing. It should be emphasized that unsaturated triaxial tests with the ATT are basically BVPs instead of so-called element tests.

Evaluation of economic loss of urban road flooding: A case of Kathmandu Metropolitan City

This paper analyzes the causes of urban road flooding and evaluates the economic cost borne by the business houses on either side of Putalisadak road section of Kathmandu Metropolitan City, Nepal as a resultant of the flood during 2018 monsoon. The calculation of losses included direct, indirect, fixed and variable cost based on before-during-after flood framework through the in-person interview conducted with systematically selected business houses in flooded studied area. The storm water runoff quantity at extreme rainfall condition exceeds the drainage discharge capacity and further gutter clogging with waste triggered the overflow of sewer mixed water causing road flood. The annual economic cost of flooding was estimated to be USD 65,579.99. Result shows that the loss of businesses depend upon the extent of vulnerability of materials towards flood and the coping strategies of the business holders. The businesses with less material damage was found to be adopting coping strategies like elevating the ground level of shops and putting glasses in the front door to prevent damages caused by water. Ironically, such urban road flooding is underrated by the Government and concerned authorities as such flood seems to be smaller in front of big river floods in Nepal. But there are huge and unseen losses due to urban floods. It is recommended that the drainage capacity should be enhanced and regularly maintained to mitigate urban flood disaster.

Predicting the effect of weir management on the discharge of a controlled drainage system in a changing climate

Subsurface drainage in humid areas prevents field waterlogging but also transports nutrients to freshwater systems. Controlled drainage (CD) reduces drainage discharge and nutrient transport from fields. Some regions are expected to experience increased precipitation in the future, requiring CD to be evaluated under a changing climate. The objective of this study was to compare the performance of CD under two weir managements for a future period (2030–2059) and historical period (1992-2021) in southeast Michigan, USA. Climate projections were obtained for the shared socioeconomic pathway 245 emission scenario. Aggressive management involved maintaining the weir height at 40 cm during the growing season and 15 cm during the non-growing season, with a longer period of managed flow compared to common management, which maintained the weir height at 50 cm during the growing season and 30 cm during the non-growing season. It was predicted that the 30-year average annual precipitation would not change significantly in the future. The 30-year average mean monthly temperature would increase by 3.0°C in the future compared to the historical period. We performed simulations using the calibrated Root Zone Water Quality Model 2 (RZWQM2). The average drainage discharge in the future indicated a 20% increase in the 30-year average drainage discharge for a field with free drainage. The CD with common and aggressive managements reduced drainage discharge by 59% and 67% for the historical period, whereas the performance of CD was even better for the future period (63% and 72%, respectively). The improved future performance of CD can be attributed to a shift in precipitation patterns, with reduced precipitation during the growing season and increased precipitation during the non-growing season. As a result, the more aggressive weir management during this period created additional opportunities for reducing drainage discharge. In conclusion, aggressive management resulted in a slightly better flow-reducing performance than common management while indicating that both methods would effectively reduce drainage discharge in the likely future scenario.

Modelling smear effect of vertical drains using a diameter reduction method

Vertical drains are used to accelerate consolidation of clays in ground improvement projects. Smear zones exist around these drains, where permeability is reduced due to soil disturbance caused by the installation process. Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process. In this study, a computationally efficient diameter reduction method (DRM) obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically. Validated by analytical and numerical results, a diameter reduction factor is analytically derived to reduce the diameter of the drain, while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain. With the DRM, the excess pore pressure u obtained from the reduced drain in the original undisturbed soil zone is accurate enough for practical applications in numerical models. Such performance of DRM is independent of soil material property. Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.

Evaluation of complications and long-term outcomes associated with 101 dogs and cats discharged with and without subcutaneous active closed-suction drains (2014-2022).

To retrospectively evaluate complications reported in dogs and cats with a closed suction subcutaneous drain that were either managed completely in hospital (Group ND) or discharged home for ongoing outpatient care (Group D). 101 client-owned animals involving 94 dogs and 7 cats with a subcutaneous closed suction drain placed during a surgical procedure. Electronic medical records (January 2014 to December 2022) were reviewed. Signalment, reason for drain placement, surgical procedure, location and duration of drain placement, drain discharge status, antimicrobial usage, culture and sensitivity results, and intraoperative and postoperative complications were recorded. Associations among variables were evaluated. There were 77 animals in Group D and 24 animals in Group ND. Majority (n = 21/26) of complications were classified as minor and were all from Group D. Length of hospitalization in Group D (1 day) was significantly shorter than Group ND (3.25 days). Duration of drain placement was significantly longer in Group D (5.6 days) than Group ND (3.1 days). There were no associations between drain location, drain duration, or surgical site contamination with risk of complications. There is a higher risk of complications associated with discharging an animal from hospital (37%) with a subcutaneous closed suction drain than removing it prior to discharge (4%). These complications, however, were primarily minor and easily managed. Discharging an otherwise stable animal to home with a subcutaneous closed suction drain may be feasible to decrease duration of hospitalization, cost to the owner, and stress for the animal.

Dam Seepage Control Uses the Blanket Layer Method

An analysis of the seepage occurring on the dam needs to be done to determine whether the size is safe to prevent collapse on the dam body. The blanket layer is a method used in seepage control. This study discussed the effectiveness of the blanket layer method in significantly reducing the seepage on the dam body by reviewing the significant drainage and stability against the uplift. A case study of Telagasari Flood Control Dam (Bendali), which suffered a water loss due to leakage on the sewer path, was carried out by performing several scenarios of analysis based on the modelling of the addition of the blanket layer, which resulted in a 98.97% decrease in the drain discharge that occurred against the conditions prior to the drain control.

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.

A Multicenter Randomized Phase II Trial Investigating the Effect of Polyglycolic Acid Sheet on the Prevention of Pancreatic Fistula After Gastrectomy with Prophylactic Lymph Node Dissection.

Pancreatic fistula after gastrectomy with lymph node dissection is associated with prolonged hospital stay and critical complications such as intra-abdominal bleeding and sepsis. Polyglycolic acid (PGA) sheets are absorbable suture reinforcement materials. A randomized Phase II trial has been planned to evaluate the effect of PGA sheets on preventing postoperative pancreatic fistula. A total of 320 patients will be recruited from thirteen institutions. Patients who are scheduled to undergo distal or total gastrectomy will be randomly allocated into the PGA group or control group, and the dissected area around the pancreas will be covered by the PGA sheet in the PGA group. The primary endpoint will be the maximum value of drain amylase concentration up to 5 days after surgery. The secondary endpoints will be as follows: transition of value of amylases of drain discharge, incidence of pancreatic fistula, incidence of intra-abdominal abscess, white blood cell count, value of C-reactive protein, incidence of postoperative complication, duration of antibiotic agents administration, duration of abdominal drainage, usage of octreotide, duration of hospital stay, incidence of bleeding in abdominal cavity, mortality, and incidence of reoperation.

Effect of Autumn Irrigation on Salt Leaching under Subsurface Drainage in an Arid Irrigation District

Non-growing season irrigation and farmland subsurface drainage play a crucial role in salt leaching and salinization control in arid irrigation areas. This study aimed to investigate the reduction of autumn irrigation quotas and drainage discharge while maintaining soil moisture retention and reducing soil salinization. Field experiments were conducted with different autumn irrigation quotas (160 mm for SD1, 180 mm for SD2, and 200 mm for SD3) combined with subsurface drainage (1.5 m drain depth and 45 m spacing). A control treatment (referred to as CK) without subsurface drainage received 200 mm of irrigation. The results showed that, after 31 days of autumn irrigation, the groundwater depth in all three subsurface drainage plots stabilized to 1.5 m, with the CK being 0.2–0.3 m shallower compared to the SD plots. The mean soil water content in the 0–150 cm soil layer of the SD1, SD2, SD3, and CK after autumn irrigation was 0.36, 0.39, 0.41, and 0.42 cm3cm−3, respectively. The combination of autumn irrigation and subsurface drainage significantly reduced the soil salt content. The mean desalination rates in the root zone (0–60 cm) soil layer were 57.5%, 53.7%, 51.9%, and 45.1% for the SD3, SD2, CK, and SD1, respectively. The mean desalination rate of 60–150 cm was not significantly different between the SD2 and SD3 (p > 0.05), and both were significantly higher than that of the SD1 and CK (p < 0.05). The drainage discharge was 31, 36, and 40 mm in the SD1, SD2 and SD3, respectively. The amount of salt discharge through the drain pipe increased with increasing irrigation quota, which was 1.22 t/ha, 1.41 t/ha, and 1.50 t/ha for the SD1, SD2, and SD3, respectively. Subsurface drainage is an effective way to prevent salt accumulation in the soil, and an autumn irrigation quota of 180 mm is recommended for leaching of salinity in the Hetao Irrigation District. These findings provide valuable insights into optimizing irrigation practices and managing soil salinization in arid regions.

Evolution of pH, redox potential and solute concentrations in soil and drainage water at a cultivated acid sulfate soil profile

Land drainage lowers the soil water table, which triggers enhanced oxidation of iron sulfide minerals in acid sulfate soils, causing acidification of fields and posing environmental hazards to aquatic ecosystems. The objective of this study was to develop a model for investigating the effects of oxidation of iron sulfide minerals and the cation exchange capacity (CEC) on the long-term evolution of pH, redox potential and solute concentrations in soil water and drain discharge. Two electron acceptors (oxygen and ferric iron) were included in the model. The model was implemented in the HP1 modeling platform (coupled HYDRUS-1D and PHREEQC-3) and applied to an acid sulfate soil profile of an agricultural field in Finland. The geochemical part of the model was tested against field observations. A comparison of different model versions showed that CEC had an essential role in mimicking the observed pH profile of soil. The drain discharge water quality was similar in the model versions both with and without CEC, but the buffering effect of CEC could be seen as lower iron concentrations. The oxidation of metastable iron sulfide minerals was three times faster than the oxidation of pyrite. Descriptions for the oxidation of both two minerals and for CEC were required to conduct long-term simulations that reproduce the observed geochemical state of a drained agricultural field. The HP1 modeling platform facilitated the testing of alternative chemical transformation processes of an AS soil profile in response to increased drainage efficiency after subsurface drainage installation.

Intraductal papillary mucinous neoplasm of the accessory pancreatic duct in the pancreas uncinate process: A case report.

Intraductal papillary mucinous neoplasms (IPMN) of the accessory pancreatic duct (APD) are very rare and their clinical significance is not known. Here, we describe a case of IPMN originating in a branch of the duct of APD within the uncinate process of the pancreas, which initially presented with acute pancreatitis. A 70-year-old man visited our medical center presenting with acute pancreatitis around the head and uncinate process of the pancreas. Computer tomography scans revealed the presence of a 35-mm cystic mass-like lesion within the pancreas uncinate process communicating with a branch of the APD. The patient was diagnosed with APD-IPMN in the pancreas uncinate process accompanied by acute pancreatitis. Conservative management of the acute pancreatitis relieved his symptoms, while duodenum-preserving partial pancreatic head resection (DPPHR-P) was performed to treat the APD-IPMN. Intraoperative exploration showed the presence of severe adhesions within the uncinate process of the pancreas and that the tumor's "peduncle" - a branch of the duct of APD - was saddling just at the front of the main pancreatic ducts. Thus, surgical removal of the tumor required special handling of the region between the main duct (MD) and APD to protect the integrity of the main pancreatic ducts. Finally, a 35*30*15 mm IPMN was successfully removed and the MD was preserved combined with ligation from the root of the APD of the pancreas. The drainage volume of the ventral tube increased by around 20-fold in 24 hours on the fourth day after surgery. The presence of high amylase levels in the drainage discharge (40713.5 U/L) led to the diagnosis of postoperative pancreatic fistula (POPF). The drainage volume remained high for 3 days. The patient was discharged and POPF was successfully managed through endoscopic pancreatic duct stenting. APD-IPMN in the pancreas uncinate process has its own characteristics of localized pancreatitis, and MD-preserving DPPHR-P not only protects the exocrine and endocrine functions of the pancreas, but it also protects the physiological and anatomical integrity. The appearance of POPF after DPPHR-P may be managed by endoscopic pancreatic duct stenting.

An analysis of the processes, kinetics and equilibrium of iron's biosorption on immobilized green microalgae

Metals including Cu, Cd, Ni, Pb, Zn, Hg, Fe and Cr can be found in significant concentrations in acid mine drainage effluent from previous gold mining operations. Even at very low levels, heavy metals and their compounds are very toxic, carcinogenic, mutagenic and teratogenic. Acid mine drainage discharge must therefore be properly treated before disposal. In this study, iron removal from acid mine drainage effluent using immobilized green microalgae is explored. The impact of pH on iron metal concentrations was studied at multiple pH values between 2 and 12 using 0.1 M HCl or NaOH solutions. At pH 6, the optimal value, 82% and 90% of Fe (II) were removed from Ca-alginate beads and immobilized Desmodesmus sp., respectively. It was shown that Fe (II) ions were biosorbed by immobilized microalgae cells in a pseudo-second-order manner. This study demonstrated how immobilized green microalgae showed potential to remove iron from acid mine drainage effluent.

Investigation of phosphorus transport dynamics using high-frequency monitoring at a subsurface-drained field in the Western Lake Erie Basin

To minimize the environmental impact of phosphorus (P) loss from subsurface-drained fields to freshwater water bodies like the Great Lakes, a detailed understanding of P transport dynamics is vital. The main objective of this study was to investigate P transport dynamics using high-frequency monitoring. We used the HydroCycle-PO4 instrument to measure total reactive P (TRP) concentration at a high resolution from a subsurface-drained farm with continuous no-till and Blount loam soil. We used a dataset containing hourly TRP concentration and hourly drainage discharge measurements in the analysis. Results showed that there was a good relationship between TRP concentration and drainage discharge (R-squared = 0.60) such that TRP had a transport-limited chemodynamic pattern, that is TRP concentration tended to increase with increase in flow during events. A 1% increase in drainage discharge resulted in a 1.36% increase in TRP load, indicating a significant increase in P concentration during high flows. We found that flow events substantially contributed to P loss (89%) because of capturing the rapid increase in P concentration during high flows. The rate of increase in P concentration during the rising limb ranged from 0.02 to 0.66 mg/L per hour. The highest 7.7% of drainage flow transported 75% of the TRP load during the monitoring period. The hysteresis pattern tended to be positive (clockwise) during the study period, indicating that preferential flow was a pathway for TRP loss. Most flow events (30 out of 36) displayed a flushing effect in which P concentration increased with rise in drainage discharge. In conclusion, high-frequency P sampling showed that management and conservation practices should target flow events to reduce P loss.

3D surface–subsurface modeling of a bromide tracer test in a macroporous tile‐drained field: Improvements and limitations

AbstractThe assessment and forecasting of nutrient loss by tile drains in agricultural areas often rely on physically based models that have adequate representations of macropores and tile drains. Macroporosity has been adequately represented in hydrological models using a dual continuum approach. However, its implementation in hydrological and solute transport models is limited to plot‐scale or to one‐ and two‐dimensional models due to the large number of parameters that are rarely available and the long computational times. The purpose of this study is to simulate a tracer test using a 3D coupled surface–subsurface model to improve the representation of the tracer concentration at the drainage discharge. A three‐dimensional HydroGeoSphere model was developed and calibrated to simulate tile drainage discharge, Br mass discharge, and hydraulic heads from a Br tracer test in a densely tile‐drained field. The conductivity of the drain was one of the most important parameters for drain discharge and solute transport simulations. The model accurately simulated drainage discharge and Br transport to tile drains. However, most of the Br peaks and the late‐time Br mass in the drain outflow were underestimated. Our simulation results indicate that explicitly representing tile drains with seepage nodes allows for a physically based, yet computationally efficient representation of Br transport behavior surrounding tile drains at field scale. However, we cannot confirm that the single‐porosity model with immobile zone is suitable for simulating the Br peaks at the drain outlet and the late‐time Br mass. Improvements to the model include the implementation of heterogeneous soil layers and the inclusion of more measured data to reduce uncertainty during calibration.

Subsurface phosphorus and nitrogen loss following liquid dairy manure and commercial fertilizer application on a clay soil in northwest Ohio.

Nutrient source has been the focus of much debate regarding the re-eutrophication of Lake Erie, despite that only 20% of nutrients applied to crops in the Western Lake Erie Basin (WLEB) originate from organic sources. However, limited data and assessments exist on the subsurface tile drainage water quality comparison between organic (liquid dairy manure) and commercial (mono-ammonium phosphate [MAP]) sources in crop production systems. Subsurface tile drainage, dissolved reactive phosphorus (DRP) and total phosphorus (TP) losses in tile drainage discharge following equal phosphorus (P) based applications of liquid dairy manure and MAP were assessed using a before-after control-impact design and four years of data from a paired field system located in northwest Ohio, USA. Nitrate-nitrogen (NO3--N) and total nitrogen (TN) losses were also examined to supplement the P findings; however, due to dissimilar nitrogen application rates, losses were assessed in a different context. No significant differences (p > 0.05) were detected in drainage discharge volumes or TP loads between the control and impact sites. However, statistically significant increases (p < 0.05) were measured for mean daily DRP, NO3--N, and TN loads from the dairy manure site. While significant, mean daily DRP differences between commercial (MAP) and liquid dairy manure treatments were only on the order of 0.01 g DRP/ha. Assuming current manure application extent and rates, when accumulated annually across the WLEB watershed, these losses are equivalent to less than 1% of target loads. These findings also help to inform nutrient management stewardship as it relates to nutrient source. Furthermore, additional research across a range of soil characteristics and cropping managements should be explored as well as the impacts of other livestock manure nutrients. This article is protected by copyright. All rights reserved.

Rationale for alternative water sources for mining regions with high environmental footprint on the example of Levikha village of the Sverdlovsk region

Introduction. Mine drainage has always been one of the main threats to the hydrosphere of mining areas, both during and after active mining. The most common method of mine water neutralization is associated with the slaked lime. On the abandoned Levikha copper-sulphide mine territory (Sverdlovsk region), acid mine drainage discharge reaches 3,000 m³/day. To neutralize acid waters, more than 400 m³/day of water with a neutral pH is required (to produce the slaked lime). Due to the worn out state of water pipe from the river Tagil, heavy losses, and frequent accidents, the neutralization station receives no more than half of the required amount of water. As a result, the neutralization technology is violated, acid mine drainage is not properly cleaned, the regulatory requirements for wastewater are not achieved, and sulfate waters with increased mineralization and metal concentrations are discharged into the river Tagil. Research objective is to substantiate the possibility of finding sources of drinking, household and process water supply for Levikha village and acid mine drainage neutralization stations by applying groundwater. Methods of research include a comprehensive approach containing research results analysis and field and laboratory research data processing. Results and discussion. Promising areas have been identified representing private catchment areas of potential water intakes with the most favorable conditions for underground runoff. A combination of the following factors was the criterion for promising areas and load points: favorable geological and tectonic conditions (the presence of tectonic faults); groundwater inflow testing results (relatively high specific flow rates of wells); geomorphological position (confinement to low relief areas, location near surface sources of groundwater recharge); hydrochemical sampling data (satisfactory chemical composition of groundwater); sanitary and hygienic situation (absence of potential sources of pollution in the local catchment area). Conclusions. The total resources of the five promising sites are 1,340 m3 /day, including 282 m3 /day for drinking purposes. Exploration and development of promising areas no. II (favorable geological and tectonic conditions within it are confirmed by the groundwater inflow testing results) and no. III (favorable sanitary and hygienic conditions) seem to be the most reasonable. These sites might cover half of the village water needs for drinking and household purposes.