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Selection of stormwater management technique was often done using rule of thumb without understanding the capacity and behavior of each low impact development (LID) technique. In this study, multi-criteria performance of each LID technique was evaluated to identify the most appropriate technology for a specific objective. Selection criteria for appropriate LID technology were derived based on different indicators such as pollutant reduction, hydraulic performance, construction, operation, and maintenance cost and other benefits of LID technologies gathered from 680 research articles. According to experts from different countries, LID technologies were mostly used for their hydraulic performance. However, few other countries also used LID technologies due to its pollutant removal capabilities. Depending on a specific objective, an LID technology may be more applicable than the other.

Post-developed catchments can generate significant amounts of pollutants that degrade environmental quality; however, the development or construction phase can already be a major source of pollutant loads. One of the major advancements in construction technology is the use of berms for erosion, sediment control, and improvement of water quality. This study mainly focused on developing design guidelines for utilizing berms in construction sites. Different types of filter media, sizing, and facility configurations were also evaluated to optimize the design of berms. Generally, woodchips and sawdust media were advantageous as compared with bottom ash and Roche volcanic in terms of pollutant removal. Based on the result of column tests, 4.75 mm woodchips and bottom ash were selected as the filter media for the pilot-scale facilities due to their high pollutant removal performance and low clogging potential. For all configurations of the pilot-scale facility, satisfactory results were obtained in terms of water quality improvement and runoff rate reduction. The guidelines developed in this inquiry can serve as a baseline for developing facilities of the same type.

Human and automobile activities have discharged various types of pollutants into the water bodies through urban stormwater runoff, producing water contamination and damaging the aqua-ecosystem. In order to manage such nonpoint pollution sources, low impact development (LID) facilities are utilized; however, LID design incorporating ecological functions was difficult due to the lack of research on biological functions. Thus, the objective of this study was to design an effective environment for LID technology through long-term monitoring results of Horizontal subsurface flow wetland (HSSF) facilities with vegetation and an infiltration trench (IT) without vegetation and comparison of microorganism growth in the sediments captured in the filter media. For IT, the major mechanism was found to be the physicochemical mechanism in the pre-treatment tank (infiltration function) and media; the major mechanisms for HSSF were found to be the physical filtration through media and the biological function of the wetland plants. Pollutant-containing stormwater runoff passes through the media part, where the physical filtration in the media and the biological function of the wetland plant life alter the forms and types of the pollutants, resulting in changes in the phyla and count of microorganisms discovered. Using woodchips as the media and planting plants with deep roots were effective means of enhancing the biological processing capability of stormwater runoff with low organic content. Also, the habitat conditions of Gemmatimonadetes and Acidobacteria for a stormwater runoff with high concentrations of phosphorus, Nitrospirae for high nitrogen content, and Actinobacteria and Firmicutes for high metal concentrations were reflected in the LID facility design and this method was evaluated as effective. When processing stormwater runoff with high degradable organic content. By considering the nutrients (pollutants) and habitat conditions of each microorganism in the LID facility design, the biological removal efficiency can be improved.

Plants applied to low impact development (LID) technologies reduce stormwater runoff pollutants through bioaccumulation of nutrients, heavy metals, and other pollutants during photosynthesis and respiration, and contributed to the restoration of natural water cycle through evapotranspiration. However, studies on the type of pollutants and environmental factors affecting Spiraea prunifolia var. simpliciflora growth LID technologies were still insufficient. Therefore, this study assessed the contaminants and environmental factors affecting the Spiraea prunifolia var. simpliciflora applied to LID techniques. In this study, a planter and a rain garden, which has different environmental conditions, were assessed. Amount of chlorophyll varied according to the TN and TP concentrations was also found to be essential for vegetation growth. In addition, it was also found that the influent concentration has a large influence on vegetation growth. The chlorophyll concentration was observed to be higher in the inflow part of both the planter and rain garden. The difference of chlorophyll content between the inflow part and outflow part was larger in the planter than that of the rain garden.

In this study, biowaste such as walnut shells (WS), cockle shells (CS), and gingko shells (GS) was evaluated for applicability as soil filter media in low impact development (LID) techniques. Biowastes used in the experiment showed light-weight, high porosity, and high permeability characteristics compared with sand or gravel which are conventionally used in LID. Especially, CS and WS showed high non-point pollutant removal efficiency due to protrusion of filter media surface and macro- and micro-porous. CS were found to be suitable for the infiltration capacity, as it showed high filtration and pollutant reduction. WS exhibited high heavy metal removal performance but was found to have possibility of organic matter leaching. GS were evaluated to be adaptable to green roof as filter media with light-weight and constant filtration capability. The findings of this research are useful for the application of biowaste as filter media in LID techniques.

Various kinds of plants are applied in low impact development (LID) facilities for the restoration of water circulation and removal of pollutants. However, de-icing substances affect plant growth retardation and cause withering of plants. The study was conducted to assess the effect of salinity on plant growth, pollutant removal efficiency, and water circulation recovery using eight kinds of plants. Selected plants applicable to LID are subdivided into three woody and five herbaceous plants. The results showed that herbaceous plants were more affected by air temperature and soil salt content than woody plants, thus showing higher withering rate. The average pollutant removal rate was over 80% due to combined soil and removal mechanisms of plants. Although withering of plants is not significant on pollutant removal efficiency, root depth, temperature sensitivity, and foliage biomass should be considered in determination of plants for enhanced LID facility performance and aesthetic value.