Taiwan Power Company-Environmental Protection at Thermal Power Plants-Water Pollutant Discharge Source

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Environmental Protection at Thermal Power Plants

Last updated: 2024-03-14

Water Pollutant Discharge Source

The Water Using Process and Wastewater Recycling Effectiveness of Thermal Power Plants

All TPC thermal power plants have general wastewater treatment systems. We will also ensure by monitoring that wastewater discharge is compliant with the Effluent Standards. Otherwise, we do our best to recycle wastewater in order to enhance water usage efficiency.

Before setting up the discharge facilities, the best discharge method is determined by numerical simulation and hydraulic model tests, in order to reduce the impact of thermal effluent on marine ecology.

Thermal Power Plant Wastewater Reuse in 2023
Power Plant	Water Source	Effluent of Treated Wastewater (tons)	Reuse of wastewater (tons)	Recovery (％)	Remark
Hsiehho	tap water	38,551	30,455	79.00
Linkou	tap water well water	436,977	320,441	73.33
Tatan	tap water	242,187	196,422	81.10
Tunghsiao	tap water	222,643	158,107	71.01	Unit 2 and unit 3 were overhauled successively in the first quarter, and the unit 1 was overhauled in May. Therefore, the amount of recycled water continuously flushed by the boiler was greatly reduced, resulting in a reduction in the recovery rate in the first and second quarters.
Taichung	tap water	675,774	675,774	100.00
Hsinta	tap water	461,652	295,834	64.08	1. In the third quarter, because the recycling water tank has been replenished to a high liquid level, and there was rainfall in July and August. The utilization rate of recycled water for irrigation and road dust suppression was low. The recycling water was not decontaminated at the recycling rate, resulting in the failure of general wastewater recycling. Reducing the recovery rate. 2. In the fourth quarter, unit 1, unit 2, and unit 4 have been shut down since October, resulting in reduced demand for boiler flushing water and general wastewater recovery as supplementary water for the bottom ash system.
Talin	tap water	532,684	324,891	60.99	In the fourth quarter, due to the shutdown of the desalination plant in October, the load on the demineralized water plant increased, resulting in an increase in wastewater. In addition, affected by underground water seepage in the coal yard area, the amount of wastewater and discharge increased.
Nanpu	tap water	72,719	25,704	35.35	1. Unit 4 and unit 3 were successively overhauled in the first and second quarters. The boiler flushing water recovery volume decreased, resulting in a reduction in the recovery rate in the first and second quarters. 2. In the third quarter, due to the heavy rain caused by the typhoon, the runoff wastewater flowed into the wastewater plant and was directly discharged, resulting in a reduction in the recovery rate.
Chienshan	tap water	7,136	7,136	100.00
Tashan	tap water	8,843	3,064	34.65	In the third quarter, the flowmeter calibration at the beginning of the month, the recycled water pipeline was not switched. Therefore some domestic sewage was released.
total		2,699,166	2,037,828	75.50

Note: The industrial wastewater had excessive salt concentration from the flue gas desulfurization process (FGD). This wastewater was unusable because it could cause serious corrosion and salination of the soil, therefore, it was not counted in the total wastewater.

Monitoring the Quality of Effluent from Thermal Power Plants

The annual average value of effluent water monitoring of each thermal power plant in 2023, including the content of hydrogen ion concentration index(PH), suspended solids(SS), and chemical oxygen demand(COD), etc. The monitoring results all meet the Effluent Standards, as shown in the table below.

Effluent
Power Plant	Water Discharge (tons/day)	pH	Suspended Solids (SS) (mg/L)	Chemical Oxygen Demand (COD) (mg/L)	Biochemical Oxygen Demand (BOD) (mg/L)
Hsiehho	21	7.9	3.6	14.6	2.5
Linkou	292.3	7.8	2.3	11.8	3.4
Tatan	124	7.4	6.5	9.7	1.9
Tunghsiao	176.8	7.6	6.6	12.2	2.2
Taichung	641	7.8	4.7	17.2	5.1
Hsinta	839	7.2	4.0	12.2	2.8
Nanpu	129	7.5	4.8	10.3	2.7
Talin	570	7.8	10.4	20.1	1.3
Standards	-	6 ~ 9	30	100	30

Note: pH is the hydrogen ion concentration index.

Thermal Effluent
Power Plant	Water Discharge (10,000 tons / day)	Water Temperature at the Discharge Point (°C)	the Temperature Difference of Surface Water 500m far from the Discharge Point (°C)
Hsiehho	229	26.0	0.05
Linkou	902	30.7	0.04
Tatan	977	30.2	0.52
Tunghsiao	796.5	30.97	0.02
Taichung	1638	30.0	0.25
Hsinta	1127	31.85	0.1
Nanpu	260	30.7	0.72
Talin	836	32.43	0.085
Standards	-	＜42	＜4