The Tamsui River (淡水河), the river with the third-largest catchment area in the nation and around which 6.15 million people live, is significantly cleaner than a decade ago, the Environmental Protection Administration (EPA) said yesterday, adding that heavily polluted areas had been reduced to 4.5 percent from 12 percent in 1998.
However, EPA deputy minister Chang Tzi-chin (張子敬) said that as 88 percent of the pollution came from domestic waste water, connection rates to the underground sewage system would need to increase before the problem could be resolved.
“As of October this year, 775,000 homes in the Tamsui River area were connected to underground sewage pipelines,” Chang said, adding that if the 6 million people in the area were calculated as 2 million families, the connection rate is low.
The EPA is employing a two-stage strategy for the river cleanup, the deputy commissioner of Taipei City’s department of environmental protection, Chan Chiung-yuan (詹炯淵), said.
While trying to connect more homes to the sewage pipeline — Taipei City has a connection of almost 60 percent, while Taipei County is a mere 18 percent — Chan said that his department and the EPA would in the meantime clean up domestic waste water with gravel-packed reactors and artificial wetlands before it flows into the river.
“As long as the connection rate is not above 80 percent, we can employ the help of wetlands and reactors,” Chan said.
A combination of nine such local cleanup facilities — totaling 50 hectares with a capacity to clean 53,000 tonnes of waste water a day — had been built, Chang said.
“Once the pollutants are removed, we also want to see the ecosystem restored,” he said.
For example, the Guandu artificial wetland, which covers 7 hectares with a 2,000-to-4,000 tonne daily capacity, is now home to a number of waterfowl and fish species that had been diminishing or even bordering on extinction, Chang said.
Rebutting media reports earlier this year, Chang added that the Tamsui water was not “clean on the Taipei City side and dirty on the Taipei County side.”
“The river runs through the city and the county; on one side is the city, on the other side is the county, so the river water is the same,” Chang said.
Chang said, however, that because the connection rate is lower on the Taipei County side, the county contributes more waste water to the river.