• Journal of Ecology and Environment
• /
• v.48 no.1
• /
• pp.110-119
• /
• 2024

Background: The Mae Kha Canal is one of Chiang Mai's most important waterways. It supports local agriculture, irrigation, and transportation as well as provides stormwater drainage to prevent floods. Due to the unregulated rapid urbanization of the city and lack of efficient waste and wastewater management systems over the past few decades, the canal has become heavily polluted. This study aimed to evaluate the water quality of Mae Kha canal through assessment of the physico-chemical water quality and coliform bacteria. Moreover, benthic macroinvertebrates were samples and assessed using the Biological Monitoring Working Party (BMWP^Thai) and Average Score Per Taxon (ASPT^Thai) as biological indices. Results: The physico-chemical showed low dissolved oxygen levels, high levels of ammonia and phosphates, and elevated levels of biochemical oxygen demand, indicating that the water quality had significantly deteriorated. The canal was found to be heavily polluted, with most sites falling into the polluted to very heavily polluted. Coliform bacteria analysis revealed alarmingly high levels of total coliform bacteria and fecal coliform bacteria in the canal. The BMWP^Thai and ASPT^Thai scores indicated poor to very poor water quality. Conclusions: The physico-chemical and coliform bacteria indicated that the water quality of the Mae Kha canal had significantly deteriorated. The biological indices also indicated the poor to very poor water quality. This study underscores the urgent need for comprehensive remediation efforts, emphasizing strategic planning, investment, and community engagement to revive the canal's ecological health and water quality.

• Journal of Environmental Health Sciences
• /
• v.45 no.1
• /
• pp.42-53
• /
• 2019

Objectives: The Yongpung reservoir in Korea is a crucial facility that supplies water to farms in its surrounding $2km^2$ area. However, its water quality is not suited to the needs of current residents who wish for the availability of environmentally friendly agricultural products and desire to use the waterfront area. The aim of this research was to evaluate the reservoir's fish and benthic macroinvertebrate distributions and determine its water quality and the heavy metal content in its sediment. This basic data can be used to establish environmentally protective plans for the Yongpung reservoir. Methods: Six sites were selected for analysis in this investigation. Three points (YP-1, YP-2, and YP-3) were evaluated for water quality and metal content in sediments; they were located upstream, midstream, and downstream of the reservoir. Samplings of the fish and benthic macroinvertebrate populations were performed at three other sites: St. 1, St. 2, and St. 3. Results: Based on chemical oxygen demand (COD) and total nitrogen (T-N) data, the quality of the Yongpung reservoir water corresponds to Class VI (very poor) according to Korea's lake environmental standards. The lead levels measured in the sediment at the midstream and downstream points of the reservoir were 76.7 and 72.7 mg/kg, respectively, while 8 orders, 15 families, and 16 species of benthic macroinvertebrates were identified in the reservoir. The ecological score of the benthic macroinvertebrate community (ESB) was between 8 and 23, denoting poor to very poor environmental conditions. Further, 4 families and 7 species of fish were identified in the reservoir, with Cyprinidae accounting for 94.3% of all observed freshwater fish. Conclusion: Based on these findings, we conclude that management plans, including the removal of lead from the sediment, are necessary to improve the quality of the agricultural water in this reservoir. The T. japonica, which cover almost 30% of the water area, must also be removed.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.3
• /
• pp.313-324
• /
• 2011

Several complaints from consumers on red or turbid waters were often filed at the same places although various efforts were made to improve water quality in the drinking water plant. The red water problems were occurred due to corrosion of main water pipe, especially at extremity. The low concentrations of chlorine indicating poor water quality were detected at the problematic location. To solve the poor water quality at the extremity, flushing techniques, i.e., conventional flushing, unidirectional flushing, and continuous flushing, were recently practiced. In this study, effects of conventional flushing on water qualities were examined by comparing turbidity and residual chlorine before and after flushing. In addition, more detailed analyses on water qualities at the tap water were conducted to learn a reduction pattern during flushing. Five items from geographic information system of water distribution were used to obtain a relationship with water quality, washing duration or amounts of washing water. The flushing was effective to meet the National Drinking Water Quality Standard with simple and relatively short time operation. The key operational parameter in flushing was amounts of washing water which should be estimated based on water quality of the consumer's tap water. The positive relationship between the residual chlorine and pipe length implied that detention time in the pipeline was the main cause of the complaints. More experiments on effectiveness of flushing are needed to determine reasonable strategies of flushing.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.11
• /
• pp.631-635
• /
• 2015

Water quality investigation was conducted for small/medium sized reservoirs in A city in June and November 2014 as a preliminary step for further use. Water quality analysis experiments were conducted for 21 reservoirs managed by a local government and water quality data were obtained from Korea Rural Community Corporation for 12 reservoirs. It was found that relatively poor water quality, not satisfied with the regulation level (somewhat poor(IV)) for agricultural use, was observed for some reservoirs and worse water quality (poor(V) and very poor(VI) grade) was observed for more reservoirs during autumn /winter season due to the decrease in water volume. Correspondingly, the trophic state was obtained as "Eutrophic" or "Hypertrophic" using the Korean trophic state index for most reservoirs. It was also revealed that significant contamination in sediments was not observed for selected 8 reservoirs considering water quality in each reservoir. The results in this study could be useful for the use of small/medium sized reservoirs as alternative water resources, tourism resources, inland fishery resources, renewable energy production sites, and anti-flooding reservoirs.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.1
• /
• pp.11-20
• /
• 2014

This research examined the effect of the quality of aggregate on concrete workability and compressive strength through an investigation into regional aggregate used in domestic ready mixed concrete plants. Through the research, it was found that aggregate for ready mixed concrete shows poor quality overall. The main factor of deterioration in the quality of the concrete is the particle size of fine aggregate and fine particle content in coarse aggregate. The quality of aggregate significantly influences concrete's workability, which is defined based on 0.08mm passage related with powder and absorption. In addition, poor aggregate quality leads to increased water content in concrete to secure workability, which is related with a decline in the compressive strength and durability of concrete.

• Journal of Environmental Health Sciences
• /
• v.28 no.2
• /
• pp.51-60
• /
• 2002

Concerning the water quality management plan about Buk-stream, Ohsip-stream and Gagok-stream water systems in this research, which objectives of abstract is as follows. The result of cleanness degree evaluation of water quality in this research, the first grade was 91% shared in Buk-stream water system. The most point of the middle and upper stream of Buk-stream was maintain extremely clean water quality. Among the researched water system, the first grade of water quality in Ohsip-stream water system was most poor, its first garde rate was 68%. In all water quality check point of Gagog-stream water system was accomplished extremely clean water quality condition of first grade of BOD. The calculation result of pollutant loading density, which were 8.2, 21.5, 4.0kg/day.$\textrm{km}^2$. respectively and basin of Buk-stream and Gagok-Stream have high development potentiality.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.113-114
• /
• 2015

This paper is to investigate the effect of poor quality aggregate source used in Korea on the mixture proportion and strength development of the high strength concrete fixed at 450 kg/m3 of cement contents. For aggregate kinds, good quality crushed stone from KS certified manufacturer and low quality crushed stone from non certified construction field are used. For fine aggregates, river sand, land sand, sea sand and mixed sand are also used. It is found that the use of low quality aggregates resulted in an increase of water demand considerably due to poor gradation of aggregate and excessive fine particles. Test results indicate that the use of low quality aggregate also decreases the compressive strength compared with that of good quality aggregate.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.6
• /
• pp.728-737
• /
• 2005

Water quality of the Hwanggujicheon is poor because of the rapid housing and development in the large area of the basin. Establishment of water quality management strategy, based on the pollution sources survey and pollutant loads estimation, has to be established for the preservation of the stream water quality of the region. In this study, waste load allocation model to achieve the water quality goal of the stream and the optimization of pollutant load reduction, was developed. Nonpoint pollutant loads calculated by runoff model in the previous study are utilized for pollutant loads estimation of the drainage areas in this study. From the application result of the allocation model, water quality goals of the Hwanggujicheon that can be achieved as a matter of fact are BOD 8 mg/L. To achieve these goals, 23% of effluent BOD loads have to be reduced in the basin.

• Journal of Korean Society on Water Environment
• /
• v.25 no.4
• /
• pp.606-614
• /
• 2009

To evaluate the biological water quality, diatom-based biological indices (DAIpo and TDI) were examined in the Sum-River and the Dal-stream. Having BOD concentrations below $2mg{\cdot}L^{-1}$ in most sites, water quality of both rivers was good. The DAIpo and TDI values ranged from 29.8 to 91.4 and from 38.7 to 93.0 respectively. From the biological water quality assessment, DAIpo and TDI for both rivers displayed fair to fairly poor water quality levels. However, the two indices showed more polluted conditions than expected from the BOD vlaues. In addition, DAIpo, having wider range of differences, appears to be more sensitive to the change in water quality when compared to TDI values. Statistical analysis using principal component analysis showed that Nitzschia palea and Diatoma vulgare might not be the appropriate indicators due to their low correlations with other indicators.

• Journal of Korean Society on Water Environment
• /
• v.33 no.6
• /
• pp.640-649
• /
• 2017

The purpose of this study is the analysis of the water quality spatial characteristics for the main stream of Nakdong River in consideration of the tributary inflow. The flow and water quality (BOD, TOC, TP) data for 32 monitoring stations located in the main stream and the tributaries of Nakdong River were collected from 2003 to 2016. From the results of the flow and water quality analyses for each site, a status map of the flow and the water quality for Nakdong River was produced. The water quality of each river section was classified according to seven river-environment standards. The water quality changes in the main stream before and after the confluence were analyzed spatially. As a result, the water quality of Kumho River, in particular the Kumho B to Kumho C section, is the worst among the tributaries. In addition, the water quality grades of the lower streams such as Nam River and Miryang are worse than that of the upper streams of the Nakdong River. In the case of the main stream, the water quality grades of the sections between the Wicheon and Nam River confluences and the section from Nakbon L to Nakbon N are relatively poor.