The main purpose of this program was to implement control and reduction of air pollutant emissions from diesel vehicles. In order to effectively lower the air pollutant emissions from the diesel vehicles in use, different means for inspection of the highly polluting vehicles were used, such as visual test of the smoke emitted from the diesel vehicles running on the roads, roadside spot checks, and reporting of black exhaust smoke from vehicles, and the related improvements were promoted. During the inspection, the gasoline of vehicles were randomly checked at the same time in order to prevent the vehicle owners from using illegal gasoline products. On the other hand, in order to expand the scope of control, regional control or diversified self-management plans were promoted in specific districts or to specific parties. Furthermore, in order to increase the vehicle owners’ willingness to come to inspection stations for vehicle inspection and obtain self-management marks, service at designated facilities was offered, making it convenient for vehicle owners to perform vehicle inspection nearby, and thus increasing the diesel vehicle inspection and control ratio. In addition, continuous guidance was given to vehicle maintenance workshops in the implementation of vehicle maintenance work, achieving the effect of air pollution source reduction, and effectively improving the air quality of Tainan City.
In 2021 the main tasks included: inspecting the vehicles equipped with selective catalytic reduction (SCR) system, authorizing vehicle maintenance workshops to become demonstration stations of smoke emission detection, assisting the Environmental Protection Bureau in carrying out diesel vehicle inspection and issuing labels on behalf of the Bureau, and helping the Environmental Protection Bureau improve the polluting level of construction machinery in order to facilitate modification, repair and improvement of construction machinery for reduction of air pollutant emissions.
The results of the various tasks in the project are summarized and explained as follows:
(1) Notifications were sent to owners of 801 vehicles emitting polluting smoke during visual inspection, achieving the target of 100% .
(2) A total of 6,634 vehicles underwent opacity test on a dynamometer, achieving the target of 118% . After the opacity test, 213 vehicles failed the test, with a failure rate of 3.2%. 153 vehicles with SCR system underwent inspections, with a goal achievement rate of 100%.
(3) A strict screening mechanism was adopted for roadside detection of smoke emission. A total of 2,428 vehicles were stopped and inspected, with 67 vehicles taking opacity test. Among them, 27 vehicle failed the opacity test, and a failure rate of 37.3% in the opacity test.
(4) Inspection service at designated facilities was offered for 56 sessions, with a total of 671 vehicles stopped on the roadside for inspection, and 674 vehicles taking opacity test. Among them, 26 vehicles failed the test, and the rest passed the test.
(5) There were 5 vehicles randomly sampled for inspection of their fuel tanks after arriving at inspection stations, 10 vehicles being stopped by roadside and sampled for inspection, and 2 vessels being sampled for inspections, with a total of 17 samples being randomly tested, and a goal achievement rate of 100%. Among the samples of gasoline, none of the cases exceeded fuel quality control standard.
(6) There were of 84 sessions of inspection or spot check carried out in specific districts, with a total of 950 vehicles stopped for inspection, and 39 vehicles taking opacity test, in which 17 vehicles failed. Visual inspection was carried out for 2 sessions, and there were 81 vehicles inspected to have no risk of pollution, with a goal achievement rate of 100%.
(7) A total of 9,891 self-management marks were issued for diesel vehicles, with a goal achievement rate of 100%.
(8) Two vehicle maintenance workshops serving as demonstration stations of smoke emission inspection, namely Jilin Vehicle Workshop in Xuejia District and Junyi Vehicle Workshop in Yongkang District, were launched, with a goal achievement rate of 100%. They assisted the Environmental Protection Bureau in carrying out inspection of diesel vehicles and issue of labels on behalf of the Bureau. There were 151 auxiliary vehicles applying for diesel vehicle inspection by vehicle maintenance workshops on behalf of the Bureau, with a goal achievement rate of 15.1%. Among them, 16 vehicles were randomly sampled for inspection, with a goal achievement rate of 10.6%.
(9) The innovative practices are to assist the Environmental Protection Bureau in completing improvement of 2 polluting construction machinery, with a goal achievement rate of 100%.
(10) For the two inspection stations, 15 quality assurance and quality control tests were performed, and drawing of control charts was completed, showing that both the testing capabilities and inspection quality of the inspection stations are normal.
(11) The average opacity rate and rejection rate of vehicles during in-station inspections and roadside spot checks have decreased year by year, and the average horsepower ratio has increased year by year. It can be seen that the pollution situation of diesel vehicles in Tainan City has significantly improved.
(12) Comparing the control situations over the years (2015-2021), the air pollution levels of large trucks of all phases have improved, and the number of Phases 1 to 3 vehicles has decreased year by year. More attention should be paid to the air pollution level of personal-use small trucks, which yet are still found to have annual improvement during roadside spot checks, with an improvement rate of about 40.2%.
(13) The reduction amounts of air pollutant emissions are as follows:
Mileage basis Item TSP(metric tons／year)
Protection Bureau Improvement after vehicle failing detection test (213 vehicles at stations, 27 vehicles during roadside spot checks, 26 vehicles at designated facilities) 4.53
Modification and repair in advance (1,045 vehicles) 17.81
Replacement of old vehicles and improvement
of pollution situation (1,296 large trucks) 52.05
Suggested total reduction amount based on driving mileage 74.39