The aims of this project include conducting relevant guidance or investigation on areas and enterprises with high pollution potential in the city, controlling pollution sources to prevent the expansion of pollution; conducting regular monitoring for soil and groundwater to achieve early warning; and handling promotion meetings for pollution improvements and certification operation. Providing citizens with a safe environment and sustaining the land resources.
The main works can be classified into regular monitoring of farmland and soil co-sampling with crops; storage system management; contaminated site certification; enterprises preventive management; sediment quality management; and response to public complaints and emergency event investigation, the executive summary is as follows:
(1). Regular monitoring of farmland and soil co-sampling with crops
The monitoring of 40 farmland plots was completed this year. Based on the "Principles for Regular Monitoring of Farmland", the monitoring results of 28 farmland plots that were systematically polluted in the past still exceeded the monitoring standards. The total analysis results of 2 farmland plots exceeded the monitoring standards, and the results of the XRF conversion value of 1 farmland plot exceeded the monitoring standard which is downstream of a contaminated site. These 31 farmland plots mentioned above were recommended to be monitored once every five years. 6 farmland plots in the Dali District were systematically polluted in the past below the monitoring standard. The monitoring result of 1 farmland plot in the Daya District located downstream of contaminated sites and drainage outlet was not under cultivation. These 7 farmland plots were recommended to be monitored once every eight years. In addition, 2 farmland plots were no longer used for agricultural purposes (parking lots, factory land) and it is recommended that the monitoring be stopped.
Soil co-sampling with crops was implemented in 61 farmland plots and 42 farmland plots in the first season and second season respectively. After confirmation on site, 1 farmland plot was not sown as scheduled, so we applied to the Environmental Management Department for exclusion. 4 farmland plots were detected with crops exceeding the standard of the tolerance of heavy metals in rice; therefore, soil XRF screening and total analysis were implemented. The water inlet of the farmland plot and its upstream irrigation canal were tested for water quality by the Environmental Inspection Department. 3 of the soil and irrigation water test results did not exceed the food crop monitoring standard /irrigation water quality standard, and one test is under analysis.
(2). Routine monitoring for farmland pollution prevention
Continuous water quality monitoring for 9 canals with high pollution potential, 4 sampling tests of water quality in irrigation canals and 5 sample re-inspections, environmental assessment of 69 irrigation groups, 313 sets of soil samplings, and the investigation of 80 sets of time-lapse resin capsule have been completed. The investigation with time-lapse resin capsules is still in progress.
In the 65 irrigation groups of the pollution control area, the soil XRF screening values exceeded soil pollution control standards at 4 locations and exceeded monitoring standards at 13 locations. In the 26 irrigation groups of the pollution warning area, the soil XRF screening values exceeded soil pollution control standards at 3 locations and exceeded monitoring standards at 2 locations. In the 21 irrigation groups of excellent protected areas, the soil XRF screening values exceeded soil pollution control standards at 1 location and exceeded monitoring standards at 1 location. Priority was given to areas that exceeded control standards to conduct time-lapse resin capsule surveys. Currently, 80 sets of monitoring have been completed, and the rest are being analyzed.
(3). Sediment quality management
There are 3 trunk lines of irrigation canals in Taichung City where the reporting values of sediment were higher than the upper limit of the sedimentation quality indicators and the soil pollution control standard, including Datuliao Canal, Liangsanshu First Canal, and Ajhaowu Second Canal. 30 sets of sediment sampling and XRF screening, 30 sets of water quality testing, and 60 sets of time-lapse resin capsule monitoring for these 3 canals were completed. The analysis of the time-lapse resin capsule is still in progress.
As of the revision period, the investigation results showed that there is a significant accumulation of heavy metals zinc and lead at points U03 to U04 on the Ajhaowu Second Canal. In the Datuliao canal and surrounding canals, the accumulation of heavy metals copper and nickel in the sediment can be observed at the water inlets. After confluence and passing through the concentrated area of factories, there is a significant accumulation of multiple heavy metals in the sediment at points U08 and U09. Depending on the situation, these areas were concluded as having high pollution potential. The main heavy metal pollution of the Liangsanshu First Canal originated from Hanxi Creek. The accumulation of heavy metals copper, nickel, and lead can be observed in the water inlets. Since the time-lapse resin capsule is being monitored, the investigation results will be added to the final version.
(4). Supervision, inspection, and certification of regulatory listed site
Within the jurisdiction of Taichung City, there are 8 pollution remediation sites, 38 pollution control sites, 1 site follows Article 7, Item 5 of the Soil and Groundwater Pollution Remediation Act, and 2 groundwater restricted use areas, totaling 49 sites. Our team conducted regular inspections and supervision on each site in January, March, May, July, and November following the provision of this project and reviewed the relevant reports, totaling 47 cases, to understand the progress and regulatory compliance of each site. The land numbers 249, 250 (part), and 282 of Wongming Section, Fengyuan District, Taichung City (L10122, Xingguo Steel Co., Ltd.) and land number 0875-0000, Youshih Section, Dajia District are sites awaiting improvement measures. Inspection of the current situation and guidance for improvement were continuously provided. B12059 Youlun Industrial Co., Ltd. failed to submit the progress report within the legal deadline. The second change of the remediation plan lacked the technician’s signature and the subsequent amendment was not made within the time limit and was rejected. Hence, this site must follow the approved content of the first plan and be disposed of by regulations. There are 10 sites in the Jincheng section of B11886 to B11895, Houli District, Taichung City. After consultation, the Third River Bureau has proposed a pollution control plan. Other sites were continuing to implement improvement work by approved plans. This plan completed the certification of 3 sites this year, including B12049 Jingshun Industrial Co., Ltd., B11772 Changshen Co., Ltd. and L10305 Yongrih Chemical Co., Ltd.
(5). Storage system report review and inspection
Report review in January 2023 (the third time in 2022), May 2023 (the first time in 2023), and September 2023 (the second time in 2023), and the completion rate of reporting was 100%. Because of the newly included storage systems in the control list, there were 58 storage systems requiring guidance and follow-up review this year. Inspections of 54 storage systems have been completed so far, of which 5 have ceased using above-ground storage, for example, Jyuye Industrial Co., Ltd. (L88A0303). 2 storage systems were temporarily closed including Deguang Heat Treatment Co., Ltd. (L0401505). After guidance, the lack of inspection forms occupies the largest proportion of insufficient compliance with regulations.
The leakage detection pipe functional test and oil gas detection were implemented based on the evaluation of 25 stations by the Environmental Management Administration and 15 stations customized in this project. 40 stations of oil gas detection were completed, and GC-FID analysis for soil gas was performed once due to the test results. The test results of soil gas monitoring wells A08 and A09 in the storage tank area of Jhenghao gas station exceeded the warning value (500 ppmV), and the GC-FID test results showed abnormally high values. The Environmental Protection Bureau guided this station to conduct self-inspection and improvement and completed the replacement of old conveying equipment and pipelines in the station with new ones in July.
The soil and groundwater investigation of Hongshu Storage and Loading Co., Ltd. was completed. The results showed that toluene, ethylbenzene, xylene, and total petroleum hydrocarbons in the soil exceeded the soil pollution control standards; meanwhile, toluene and total petroleum hydrocarbons in the groundwater exceeded the second-category control standard for groundwater. It is recommended that this gas station be announced as a regulatory listed site in accordance with the relevant provisions of the Soil and Groundwater Pollution Remediation Act.
(6). Enterprise land pollution prevention and management
2 briefing meetings for preventive management were held before May 18. The review of the self-assessment forms of 41 enterprises and on-site environmental assessment of the site in the prevention management group were completed and soil verification was executed on 4 enterprises. The concentration of pollutants detected in the soil exceeded the soil pollution control standards in 3 enterprises and exceeded the soil monitoring standard in 1 enterprise.
In addition, the self-management groups were assisted in filling out reports and proposing self-prevention management plans. From September 15 to October 2, inspections of 16 enterprises of the self-management group and 18 enterprises of the supervised-management group were completed.
(7). Emergency response operation
Four emergency response operations were completed, including (1) Stable isotope environmental identification case of groundwater trichloroethylene contamination in Taichung Industrial Park: Conducted isotope analysis of groundwater on monitoring wells located in groundwater restricted use zone (now abolished) and monitoring wells in the upstream enterprise. The result indicated that the pollution plumes have the same characteristics; thus, the groundwater restricted use zone was announced as a pollution control area. (2) Groundwater verification of illegal disposal cases at a sand and gravel plant found that the content of heavy metals was below control standards. (3) The investigation of sediments around the enterprise in the Taiping District: After correlation investigation, the heavy metal characteristics of the sludge cakes produced by Tangjhen Company and Jiashihbao Company matched the sludge cakes adjacent to the drainage ditch. It implied that these two companies contributed to the heavy metal pollution of sediment in the sixth water supply of the Toubiankeng Canal. (4) In response to the illegal dumping incident in Fanzihyuan Canal, Wuri District, the sediment detection and analysis results indicated that the upstream and downstream of the dumping place had similar environmental characteristics, both were dominated by the heavy metal zinc. It seemed that heavy metals kept accumulating in the sediment downstream of the dumping place. It is recommended that attention be paid to changes in sediment quality in this canal in the future.
(8). Other works
In addition to implementing various monitoring and investigation tasks to maintain the quality of soil and groundwater in the jurisdiction, this project assisted in the compilation of this year's industrial park monitoring management and testing data, completing 71 soil pollution assessments and test reviews, and 35 on-site inspections. Continuing to manage the progress of this year's performance appraisal and cooperate with relevant requirements, proposed an innovative operation; uploaded and managed the data of the soil and groundwater information management system, assisted in various administrative tasks, and handled soil and groundwater pollution improvement promotion meetings.
