In order to further improve the environmental quality of water bodies in the basin under the jurisdiction of Taichung (hereinafter referred to as the city) and show the effectiveness of river pollution control, the Environmental Protection Bureau specially formulated and promoted the "2021 Comprehensive Management Plan for Taichung’s Water Pollution Control" (hereinafter referred to as the plan) in 2021, in the hope to conduct a rolling review of the relevant pollution control measures of key river basins within the jurisdiction through this plan, and further conduct on-site inventory of pollution sources of key stations, so as to put forward the pollution reduction action plan of key stations, and at the same time achieve the annual objectives of water pollution control assessment through the comprehensive management of relevant water pollution control plans.
1. Objectives and Strategies of Water Quality Improvement in the Three Major Watersheds of the City
Among the three major watersheds, Wuxi is the primary watershed to be improved. The polluted area is from Wuxi Bridge to Dadu Bridge, and the key stations are Dadu Bridge and Xinan Bridge. The primary pollution source is domestic sewage, followed by industrial wastewater and livestock wastewater in some areas.
It is suggested that the improvement strategies of general water quality projects include accelerating the construction of the public sewage sewer system, increasing the construction and operation of the interception station system, and promoting the installation and proper operation of the water purification facilities in key river sections or branches. The business control measures include strengthening the inspection and management of quarries and promoting the reduction of ammonia nitrogen in key river sections (ammonia nitrogen survey in effluents, ammonia nitrogen reduction control measures, and assessment of the promotion scheme of ammonia nitrogen control). The improvement strategy of heavy metal water quality projects focuses on business control, including the detection of raw wastewater and effluent quality of businesses, strengthened inspection and control of focused heavy metal discharging entities, negotiation of independent reduction with entities which are not subject to the 2021 standard of stricter heavy metal control, setup of mobile water quality sensors, inspection of regulated businesses in the total volume control area, and hierarchical inspection of key businesses and inventory of non-regulated businesses, so as to reduce the pollution load of businesses.
Secondly, it is suggested to give improvement priority to the section of Dajia River from Houfeng Bridge to the expressway bridge; the key measuring station is the expressway bridge, the indicator pollutant is BOD, and the primary source of pollution is industrial wastewater, followed by domestic sewage. The suggested strategic business control includes the inspection and control of important pollution sources and improvement of the treatment efficiency of the joint sewage treatment plant in the industrial zone. For the domestic sewage part, the strategies include continuously promoting the public sewage sewer system user takeover project and setting up interception stations, promoting the construction of the planned sewage sewer system, inspecting community-specific sewers and giving guidance to improve the operation rate, promoting the setup of grease interceptors in markets and restaurants not up to the regulated scale, and promoting the regular cleaning of septic tanks.
Da’an River flows through the south of Miaoli County and the north of Taichung, and it is suggested to give priority to the improvement of the section from Zhuolan Bridge to Da’an River Bridge. The key measuring station is Da’an River Bridge measuring station within the jurisdiction of the city, and the indicator pollutant is SS. The primary pollution source of this section is domestic sewage, followed by industrial wastewater. The suggested strategies include proper treatment of domestic sewage and strengthened inspection and management of quarries; the common strategies include cross county and city cooperation plans for water quality, pollution control of rivers and drainage works, and pollution control of non-point sources.
2. Assistance in the Comprehensive Management of Water Pollution Control Plan
(1) Cooperation with the Environmental Protection Agency in the assessment for water pollution control of the city
Assistance was rendered to the Environmental Protection Bureau in handling the water pollution control assessment and comprehensive management of the plan, including assistance in the trial calculation of the score of the 2021 assessment every month, and the quarterly consolidation of key station pollution reduction performance; analysis was performed for projects with lagging scores or failing to meet the objectives, the trial calculation results were presented at the monthly progress review meeting, and the improvement scheme was put forward to the Environmental Protection Bureau.
As of the end of December, 2021, the score of the trial calculation for assessment indicators 1 to 9 (90 points in total, and the remaining 10 points are the scores of on-site briefing) was 84.79 points, and the score deduction was mainly due to the lagging score of the ratio between the actual irrigation volume of biogas slurry and biogas residue in animal husbandry and the approved irrigation volume under the indicator of promoting the resource utilization of animal husbandry manure and urine (achievement rate 76.6%). In addition, the results report of the 2021 water pollution control assessment plan was submitted on November 5 and the results briefing was submitted on November 19.
(2) Review and control of the implementation progress of the commissioned water pollution control plan
This plan helps to master the implementation progress of the commissioned plan, and has assisted in holding 12 progress review meetings (from February 2021 to January 2022). The briefing materials submitted by each commissioned plan are reviewed every month, and improvement suggestions are put forward for items that fail to meet the scheduled objectives or have incomplete data. On the review of the progress of commissioned plans, at the end of July, the implementation progress of the works under the "2021 Plan for Taichung River Basin Total Pollution Volume Control, Audit on the Collection of Water Pollution Fees and Inspection of Water Pollution Sources" was behind schedule, and the corresponding assessment indicators of the Environmental Protection Agency included "I. Promoting the resource transformed from livestock manure and urine", "IV. Improving the implementation of laws and regulations and the quality of water system data", "V. Other administrative compliance matters" and "VI. Water quality improvement effectiveness of key measuring stations". In addition to providing improvement suggestions at the work inspection committee, this plan also assisted in tracking the implementation. As of the end of November, the progress of the planned works has met the contract requirements. The assessment indicators of the Environmental Protection Agency have reached the predetermined objectives, except the indicator of promoting the resource transformed from livestock manure and urine which was lagging behind.
In addition, with reference to the implementation of various water pollution control works this year and the relevant subsidy plans of the Environmental Protection Agency, the plan assisted in developing the key works of the 2022 water pollution control plan, including the comprehensive management of water pollution control, inspection of water pollution sources and audit on the collection of water pollution fees, reduction, prevention and control of total wastewater discharge volume, and promotion of ammonia nitrogen recovery from livestock wastewater, in order to continuously promote the control of water pollution and improve the water quality of river basins in the city.
3. Operation and Maintenance of Mobile Water Quality Sensor and Photographic Equipment
Under this plan, 27 water quality sensors were set up in the jurisdiction. During the implementation of the plan, the operation and maintenance of the sensors were inspected regularly and calibrated at least once a month to ensure the stability and accuracy of water quality monitoring values. Regular statistical analysis of the monitoring data of the water quality sensors was performed, abnormal characteristics and frequent time periods were summarized, and the suspicious upstream pollution sources were screened. A total of 12 abnormal water quality points were reported, and the Environmental Protection Bureau has successfully cracked 4 water quality abnormal cases. Among them, two metal surface treatment companies were found by the survey station of the Xiapi trunk line to have discharged wastewater exceeding the pollution standards (one with pH exceeding the standard, and the other with SS 27 times, COD 10 times and total chromium 2 times above the standard); the fine for the former was NT$75,000, and the trial calculation result of the fine for the latter was NT$2,772,000. A metal surface treatment company was found by the Qixing drainage survey station to have discharged wastewater above the pollution standard (pH 11.9, and SS 24.7 times above the standard), and a fine of NT$1.482 million was levied. A food processing factory was found by the survey station outside the Jiati embankment to have discharged waste water to pollute the water environment in violation of Article 30 of the Water Pollution Control Act, and a fine of was NT$30,000 was levied. A food manufacturing company was found by the survey station of lane 206, Xinren Road to have violated the provisions of paragraph 1, Article 7 of the Water Pollution Control Act, and a fine is in the process of being levied.
In view of the frequent occurrence of dead fish incidents due to low dissolved oxygen over the years, cloud cameras were set up at Dongda Creek (upstream of the Fazi Creek) in Xitun District, the Liuchuan Liukang Bridge (Hanxi) in Wuri District, the Liuchuan Fuxing North Road Bridge (Hanxi) in South District and the Jiujiasan bridge (Fazi Creek) in Sikuaicuo Ditch, Xitun District to regularly monitor the water environment. In compliance with the Environmental Protection Bureau's requirement, a cloud camera was installed at the Yu X pig farm to record real-time kitchen waste recycling and cooking conditions.
In addition, reporting was immediately made to the Environmental Protection Bureau through a LINE group when abnormal monitoring pictures taken by the photographic equipment were found, and when dead fish groups were found on the water surface and abnormal discharge of wastewater (sewage) was detected during inspection. Due to low rainfall before May this year, dead fish group cases were frequent because of lower river drainage level and low dissolved oxygen. Dead fish groups were found 9 times through the photographic equipment, and abnormal discharge of wastewater (sewage) was detected 4 times.
4. AI Analysis and Application of the Water Data Collection System Established
In order to help the Environmental Protection Bureau improve the efficiency of water area management, this plan specially established a water data collection system to serve as the basis of future intelligent management and collects various water quality data, including periodic survey stations of the Environmental Protection Agency, periodic survey stations and water quality sensors of the Environmental Protection Bureau, and discusses its application value, feasibility of introduction and introduction method.
AI analysis and applications include "Application of dissolved oxygen AI prediction to early dead fish warning" and "Tracking module of leading water quality industry". The “Application of dissolved oxygen AI prediction to early dead fish warning” module has been completed; the meteorological conditions of the Weather Bureau and the water level data of the Water Resources Bureau were imported, and together with the environmental characteristics of each water area, the dissolved oxygen computer was built with AI algorithm to predict the dissolved oxygen status of each water area in the next 7 days, and the predicted results are displayed in the form of dissolved oxygen calendar. The analysis results of the predicted and measured values show that trends of the predicted and measured values of dissolved oxygen on Lincuo trunk line, the midstream of Wuqi Big Drain, and Xiehe 3rd Bridge of Dongda Creek are similar. On the "Tracking module of leading water quality industry", the Han Creek in the upstream of Dali Creek was taken as an example for model building and testing with half a year as a cycle, and the data of the periodic survey stations of the Environmental Protection Agency and the Environmental Protection Bureau were integrated for analysis. The relevant water quality project group in the quarter was first obtained through simple correlation, and then the frequently occurring water quality parameters in the last six months were found out through Apriori classification to judge the corresponding industries. Finally, based on the changes of leading industries over the years, LSTM is used to predict the major polluting industry affecting future water quality changes.
5. Other Works Related to Water Pollution Control
In the implementation of water pollution control related work, this plan assisted the Environmental Protection Bureau in handling the National Water Pollution Control Business Review Meeting to guide pollution improvement for the upstream undertakings of key stations, collect research and media publicity materials related to water pollution control, and take care of other administrative matters. The National Water Pollution Control Business Review Meeting has been completed; on the first day, the topic discussion was held in the Rose Hall of Fullon Hotel in Lihpao Resort; on the second day, the environmental education site was visited in the Water Resources Recovery Center of Shigangba Water Source Specific Area. In addition, for the guidance and improvement of pollution in the upstream undertakings of key stations, three guidance and improvement operations of livestock wastewater (sewage) treatment facilities have been completed. The preliminary assessment was to check the compliance with livestock farm laws and regulations, the operation and implementation of treatment facilities and the water quality of treatment units, and provided improvement suggestions to the operators through the self-check and operation leaflet of wastewater treatment facilities. Re-assessment experts and scholars provided suggestions to the operators concerning the problems found in the preliminary assessment and improvement of the efficiency of facilities. This plan also helped track the improvement status of operators.
As for other administrative matters, there were 247 sanction cases under the municipal water pollution regulations, including 101 cases for non-regulated enterprises and 146 regulated enterprises, with a total fine of about NT$43,661,673,000. The bulk of the cases was in violation of Article 30 and paragraph 1, Article 7 of the Water Pollution Control Act. For the review of special responsibility application setting, the review results showed that there were 9 non-compliant enterprises, 14 enterprises requested supplemental documents, and 133 enterprises pending review. For the Qingxi project, 24 inspections have been completed for the catering industry and tourist hotels (restaurants) under the jurisdiction of the government. One of them did not obtain the discharge permit (document) before discharging the domestic sewage and hot spring water into the surface water body through the existing wastewater treatment equipment, and violated the relevant provisions of the Water Pollution Control Act. 232 restaurants and stores (such as snack bars) with public complaints were inspected, and the violation by 31 of them were confirmed after on-site inspection. For the construction sites that should have been deregulated, the comparison of the name lists with the dates of deregulation between 2017 and 2020 has been completed. The comparison result shows that there were 209 sites that should have been deregulated, and most of them were in Beitun District. The relevant information has been provided to the Environmental Protection Bureau for subsequent deregulation.
In addition, in order to facilitate the Environmental Protection Bureau’s exhibition of the relevant implementation results of water pollution control, this plan assisted in the production of the picture card showing that tableware needs to be wiped with waste paper after use to remove the oil on it, and made relevant briefings on water pollution control. In addition, news media were entrusted to publish relevant newspaper and magazine articles with the theme of water quality sensor, and videos of water pollution related inspection results in recent years were produced with technology as the theme for the purpose of policy advocacy and result exhibition.