Environmental Protection Bureau specially made and pushed forward the “ Comprehensive Management Plan for Water Pollution Prevention and Control in Taichung City in 2020” (hereinafter referred to as “this Plan”) for Taichung City (hereinafter referred to as “the City”) to improve the quality of water bodies in the river basin under its jurisdiction and show the effectiveness of river pollution remediation, hoping to check the baseline data of various pollution sources under the jurisdiction to be a basis for the development of relevant pollution remediation strategies through this Plan, and to gradually improve the quality of water bodies in the river basin through cross-departmental coordination rolling self-criticism and amendments for the City’s three major river basins, as well as achieving the annual evaluation standard of water pollution control evaluation by comprehensively managing relevant water pollution control plans.
The implementation period of this Plan is from February 7, 2020 (bid opening date) to December 31, 2020. The implementation rate of this Plan reached 100% as of December 30, 2020, and all work items were completed on schedule. The results of the final report are summarized as follows:
1. Check of Baseline Data of Pollution Sources Under the Jurisdiction of the City
For the use of the water pollution source control data management system to screen out the City's water pollution source controlled business, of which the number is 4,086 in the City. The top 5 industries are construction site, community sewer with a flow rate of less than 250 CBM / day, metal surface treatment industry, animal husbandry (1) applicable to non-herbivores and electroplating industry; the top five administrative districts for the business under surveillance and control are Xitun District, Taiping District, Beitun District, Nantun District and Dali District. We have Taichung Industrial Zone, Taichung City Precision Machinery Innovation Technology Park, Central Taiwan Science Park, Ministry of Science and Technology - Qixing Industrial Park Area, Taichung Export Processing Zone, Wufeng Industrial Zone, Dali Industrial Zone, Dali Renhua Industrial Park, and Dajia Youshi Industrial Zone , Taichung Port Export Processing Zone, Central Taiwan Science Park, Ministry of Science and Technology - Houli Industrial Park Area, Shengang Fengzhou Technology Park and Central Taiwan Science Park, Ministry of Science and Technology - Taichung Industrial Park Area, a total of 12 industrial zones’ dedicated sewage systems, totaled to 401 businesses put under surveillance and control. This plan has set up a pollutant discharge load inventory and drawn a distribution map of pollution in the river basin as a reference available for the Environmental Protection Bureau to track and verify pollution sources.
Moreover, an analysis on approval data of each business under surveillance and the regular inspection report data of 2019 was performed to judge whether the operating status of the wastewater treatment facilities, dosing situation, operating parameters according to the regular inspection report are reasonable, and whether the inquiry through the EEMS system violates effluent standard, dividing the businesses under surveillance into three levels, regularly screening out the list of classified examination for the three major river basins with rolling method, wherein a total of 28 suspicious objects were at the first level. Inspection methods of in-depth, project, and total quantity control are advised. The second level classified as the functionally unstable objects reached up to 61, and a functional evaluation method is advised. The third level were continuous tracking objects totaling 1,036, and it is recommended to use general inspection methods.
2. Water Quality Improvement and Remediation Goals ＆ Strategies for the Three Major River Basins in the City
The major river basins under the jurisdiction are Da’an River, Dajia River and Wu River. This Plan analyzes the water quality and pollution causes of each river basin over the years, comprehensively evaluates pollution remediation priorities, key monitoring stations and representative pollutants, and prepares improvement strategies and suggestions for pollution sources, as well as collecting and integrating the relevant promotion results of the bureaus’ water pollution control, integrating them into the City's overall management strategy in water pollution control and management.
Da’an River’s priority remediation section is between Baibufan Bridge and Zhuolan Bridge. The key monitoring station is Zhuolan Bridge. The representative pollutants are BOD and SS. The major pollution source is domestic sewage, followed by business wastewater. The short-term (2011-2012) goals are quality improvement set to achieve an annual average RPI value of less than 2 in the entire basin, maintenance of level of no (light) pollution, achieving a rate of more than 62% in the four items of water quality. The crucial strategies including wastewater and sewage being properly treated at the camping field, and inspection management being strengthened for earth-rock fields and amusement parks are advised
Dajia River’s priority remediation section is between Houfeng Bridge and Dajia River Bridge. The crucial key monitoring station is Dajia River Bridge, and the representative pollutants are BOD and SS. The major pollution source is domestic sewage, followed by livestock wastewater and business wastewater. The short-term (2011-2012) goals are quality improvement set to achieve an annual average RPI value of less than 2 in the entire basin, maintenance of level of no (light) pollution, achieving a rate of more than 78% in the four items of water quality. The key strategies including continuing to promote the public sewage system household connection-pipes engineering and the establishment of interception stations, promotion of oil trap installation in the market and restaurants being not subject to surveillance and control, improvement of ammonia nitrogen wastewater treatment efficiency of the combined sewage treatment plant in the industrial zone, and the resource utilization of livestock manure are advised.
The Wu River pollution hot spot is between Wu River Bridge and Dadu Bridge. The key monitoring stations are Dadu Bridge and Xi-nan Bridge. The major pollution source is domestic sewage, followed by business wastewater and livestock wastewater in some areas. The short-term (2011-2012) goals are quality improvement set to achieve an annual average RPI value of less than 3.5 in Dadu Bridge and less than 4.0 in Xi-nan Bridge; while the long-term (after 2029) goals are all to reach light pollution level. The recommended crucial strategies for domestic sewage include the continuous promotion of the construction of public sewers, addition and operation of interceptor station systems, construction of water purification facilities in key river sections, and the use of regenerated water in water resources centers; business control includes the promotion of investigations into heavy metal pollution potential area aiming at Dali River, expanding and tightening of specific areas’ effluent standard for heavy metal, hexavalent chromium project inspection, and investigation of high pollution potential canal channel in the upstream of Datuliao Canal Intake to mitigate heavy metal pollution problems, additional promoting general investigation of ammonia nitrogen in effluent and ammonia nitrogen reduction control measures, mitigating the concentration of ammonia nitrogen in Dali River, with the installation of mobile water quality sensors, strengthening inspections of earth-rock fields, business classification inspections and guidance on check-over of businesses being not subject to surveillance and control to reduce business pollution.
3. Transaction of Water Pollution Control Evaluation Plans and Evaluation Operations
Assisting the Environmental Protection Bureau in transacting water pollution control evaluation plans, including monthly assistance in computing the results of the 2020 evaluation and quarterly collecting along with organizing the performance of pollution reduction at key monitoring stations on an aggregate basis, and analyzing the reasons for the projects that have fallen behind or failed to achieve the goals and putting forward suggestions for improvement, as well as assisting in writing annual evaluation reports and briefings on the results of river pollution remediation.
The City’s written results for the evaluation plan were 78.02 points, of which (1) the allotment of water quality improvement effect of key monitoring stations was 40 points, in which 29.92 points were awarded; (2) the allotment of promotion of animal husbandry manure recycling was 12 points, in with 10.76 points were awarded; (3) the allotment of implementation of water pollution control expenditure was 10 points, in with 9.62 points were awarded; (4) the allotment of collection and implementation of water pollution control fee was 6 points, in which 6 points were awarded; (5) the allotment of law enforcement degree and water system data quality improvement was 11 points, in which 10.72 points were awarded; (6) the allotment of other administrative coordination matters was 9 points, in which 9 points were awarded; (7) the allotment of regulations propaganda, innovation and effectiveness was 2 points, in which 2 points were awarded. In addition, the 2020 water pollution control evaluation plan results report and briefing were completed, and the results report was submitted to the Environmental Protection Administration on November 5.
4. Review and Control of Implementation Progress of Water Pollution Plans
This Plan assists in grasping the implementation progress of the commissioned Plan. 11 progress review meetings (February 2020 through December 2020) have been transacted, wherein the briefing data submitted regarding each commissioned plan are reviewed every month, and the improvement suggestions for projects failing to achieve the goals set beforehand or the projects with incomplete data. As of November, the implementation progress of the five commissioned plans was in accord with the targeted number planned at the beginning thereof.
In addition, referring to the implementation of all water pollution control works this year and the water pollution control subsidy program of the Environmental Protection Administration, the key points of the 2020 water pollution control plan have been prepared, including the comprehensive management level of water pollution control, water pollution source inspection and water pollution control fee collection aspect, reduction of the total quantity of wastewater discharge and the prevention and control aspect as well as the promotion aspect of recycling of livestock wastewater and ammonia nitrogen in order to continuously promote water pollution control and improve the water quality of the City’s river basins.
5. Analysis of Water Pollution Incidents over the Years
This Plan organizes and analyzes, on an aggregate basis, a total of 514 data about water pollution incident notification records, river water quality abnormality notification and subsequent event data being notified thereof through processing platform between 2013 and 2019. The major administrative districts are located in Wuri District, Daya District and Tanzi District, centering on the tributaries of Wu River. The main river sections include Liuchuan Drainage Ditch, Erchong Floodway, Tou-Bian-Keng River, etc. In addition, Wenliao River, Qingshui Drain and Wuqi Drain near the sea gate are also the places where pollution incidents frequently occur. Most of the causes are dead fish incidents arising from low water level, water cut-off, low dissolved oxygen, and temperature abnormalities.
Besides, the river sections which are prone to hypoxia targeting the dead fish incidents center on Han River (Erchong Floodway), Wuzhangli Branching, upstream of Fazi River (Dongda River), Zhongxing Drain and Wuqi Drain. In addition, the months of the most frequent occurrence of dead fish incidents were Decembers in 2015, 2016 and 2018. Among them, November 2018 through February 2019, the 4 months were the most frequent period in the past. The weather data showed that the winter temperature in 2018 was higher than the average value, and the rainfall was generally low. It is speculated that when the temperature is high during the dry season, fish deaths are easy to occur. Moreover, in order to mitigate the complaints about occurrence of dead fish, this Plan organized 2 expert and scholar interviews (Professor Huang Ta-Chun and Assistant Professor Liu Chi-Chang) and 3 cross-departmen interviews (respectively are the Third River Bureau, Taichung Management Office of Irrigation Agency and the City’s Water Resources Bureau), and held a cross-departmental opinion exchange meeting on the dead fish incident on November 18, discussing solutions on the dead fish problem, AI applications to joint early warning and response system, and cross-departmental cooperation methods. In addition, to river sectors where dead fish incidents due to hypoxia are of high occurrence, 11 recommended locations are screened out, and a water quality sensor layout of the water quality sensor test application plan is provided for reference.
