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Land use changes, specifically the growth of impervious areas due to urbanization, exacerbate non-point-source pollutants in stormwater runoff, surpassing discharge from point sources in Korea. The application of nature-based solutions, such as constructed wetlands (CWs), is becoming popular for stormwater treatment, but challenges arise when background concentrations are overlooked, leading to reduced pollutant removal efficiency. This study aims to propose a plan for the sustainability of CWs by evaluating design appropriateness and utilizing existing monitoring results. The evaluation of 63 CWs reveals that meteorological factors, specifically antecedent dry days and rainfall depth, have significant impacts on urban stormwater runoff quality in various land uses, affecting the performance of CWs. Designing CWs considering land use is crucial due to the considerable concentration variations across different land uses. Improving CW performance requires proper maintenance strategies to ensure effective pollutant removal mechanisms, especially for poorly degradable organic substances post treatment. Rainfall characteristics play a pivotal role in CW design and operation, affecting capacity, efficiency estimation, and maintenance frequency. Considering various factors such as land use, watershed characteristics, and ease of maintenance is essential when utilizing CWs. This study's findings contribute to the design and operation of future CWs, emphasizing the need for continuous performance analyses through long-term monitoring. [ABSTRACT FROM AUTHOR]

Evaluating the functionality of small and decentralized low-impact development (LID) technologies often requires extensive labor, time, and costs for water quality analysis. In order to reduce these in an infiltration trench in South Korea, monitoring data gathered over a period of 8 years were used to determine its long-term performance, establish a stormwater quality estimation model, and develop a comprehensive evaluation tool. Our findings show that the infiltration trench can treat up to 90% of the stormwater runoff from a paved road but would require annual maintenance to minimize the reduction in infiltration capacity. The facility was able to remove an average of 83% of total suspended solids (TSS), 75% of biochemical oxygen demand (BOD), 80% of chemical oxygen demand (COD), 76% of total nitrogen (TN), and 79% of total phosphorus (TP), with the highest removal efficiencies observed after maintenance was conducted. Rainfall depth and air quality parameters (i.e., PM2.5 and PM10) were found to be positively correlated with TSS, COD, TN, and TP. These parameters were then used to develop a model for the estimation of influent stormwater quality, which can help in estimating the effluent water quality based on the average removal efficiencies. Furthermore, a comprehensive evaluation tool considering indicators such as treatment efficiency, cultural benefits, and facility and operating conditions was established through the analytic hierarchy process (AHP). Aside from determining the facility's overall efficiency, this can also serve as a diagnostic tool to identify whether maintenance is needed or not. While atmospheric and hydrological characteristics differ in different regions, and the results may vary if applied in other facilities, this study can serve as a guide to the effective and efficient evaluation of similar stormwater management facilities in South Korea. [ABSTRACT FROM AUTHOR]

Agricultural areas utilize various types of agrichemicals to enhance crop growth and production. As a consequence, areas treated with excessive amounts of agrichemicals become primary sources of environmental pollutants. This study was conducted to analyze the different types of phosphorus (P) in the agricultural soils in Deacheong Lake Watershed. The effects of cultivation activities in the availability of nutrients that can potentially cause eutrophication of receiving water bodies were also assessed. The total phosphorus (T–P) and phosphate (PO4-P) concentrations in the tributaries draining into the Daecheong Lake were found to be three to seven times higher than the T–P and PO4–P concentrations in Daecheong Lake. The P concentrations in the waterways exhibited significant correlations (p < 0.05) with the soil P, implying that agricultural activities may influence the water quality in Daecheong Lake. Dry field soils had higher T–P concentrations (1246.1 ± 579.9 mg/kg) as compared to paddy fields and in situ soils due to the continuous accumulation of P in the soil strata. Non-apatite inorganic phosphorus (NAI-P) was the most dominant type of P in paddy field soils, whereas organic-P had the highest fraction in dry field soils. Paddy fields can have higher potentials of contributing to eutrophication, since NAI-P is an indicator of algal-available P. T–P concentrations in agricultural soils planted with different crops follows the order: tobacco > corn > perilla > soybean > Chinese cabbage > barley > sweet potato > garlic > potato > red pepper > rice. Generally, shifts in agricultural practices can be used to assess the contribution of agricultural areas in the eutrophication potential of water bodies. [ABSTRACT FROM AUTHOR]