Industrial growth causing city to suffer acid rain
City News – March 08, 2007

Adianto P. Simamora, The Jakarta Post, Jakarta

While much of Jakarta’s groundwater has been seriously polluted, rainwater in the capital is also unfit for consumption due to its high level of acidity.

Agus Maryono, an expert from the Yogyakarta-based Gadjah Mada University, said atmospheric pollutants had affected the acidity of rainwater.

“The quality of rainwater is far below the healthy level and is no longer fit for drinking. This is mainly due to the high level of air pollution in the city,” he said.

Data from the Meteorology and Geophysics Agency (BMG) shows that the pH level of Jakarta’s rainwater was 4.5 in January 2005, far lower than the international average of 5.6.

Agus warned Indonesia could be following in the footsteps of the U.S., where acid rain is becoming a serious problem.

In 2000, the U.S. recorded acid rain with a pH of 4.3.

“Low pH levels were found in rainwater in all cities across the U.S.,” he said.

The acid in acid rain comes from two types of pollutants: nitrogen dioxide (NOx) and sulfur dioxide (SO2). They are emitted primarily through the burning of fossil fuels. When these pollutants reach the atmosphere they combine with gaseous water in clouds and change to acid.

Acid rain can cause vegetation and building materials to decay. It also affects lakes, streams, rivers and ponds by increasing their acidity until fish and other aquatic creatures can no longer live there.

Agus issued the warning during a discussion on harvesting rainwater.

The discussion, held Wednesday at TVRI station’s office, was attended by State Minister for the Environment Rachmat Witoelar and Budirama Natakusumah, the head of the Jakarta Environmental Management Agency.

Agus said the government had yet to pay attention to the possibility of acid rain in the country.

During the floods in the city last month, many Jakartans were reportedly forced to drink untreated rainwater.

The BMG monitors the rainwater quality in the country from 27 stations. The stations check the level of PH, water conductivity, manganese (Mg), calcium (Ca) and SO2.

According to BMG data, the rainwater in Jakarta — the first city in the country to have issued a bylaw on air pollution — had the lowest pH level in the country in January 2005, followed by the rainwater in Jayapura and Bandung. The highest pH level was 5.7 in Makassar, South Sulawesi.

Flooding and water shortages are yearly occurrences in the city.

The agency reported that 80 percent of the groundwater in wells with depths of 10-20 meters was polluted mainly by E.coli or bacteria.

Agus said acid rain could be treated through the use of percolation pits.

“The pollutants are filtered out during the percolation process.”

The government and the administration have been promoting the use of percolation pits since the floods.