River trailblazer: An officer operates an excavator to fork out mud and waste from Kali Mati River in West Jakarta. JP/Agnes Winarti
Few people might realize that their home septic tanks contribute to pollution in the city’s major rivers.
Rina Suryani, head of environmental pollution control at the city environment agency (BPLHD), said many residents had the wrong idea about what constituted a good home septic tank, believing it was one that was never full and, therefore, did not need to be emptied.
“That’s completely wrong,” Rina told The Jakarta Post recently.
“They are unaware that their septic tanks are heavily contami-nating the soil,” Rina said about conventional septic tanks used by most city residents where the tank is buried underground, allowing the liquid waste to seep into the ground and contaminate groundwater and rivers.
In 2007, BPLHD reported that 94 percent of the samples taken from 66 spots along 13 major rivers flowing through the city were heavily polluted.
Earlier in 2006, the agency, which conducted the same sampling on the same spots, found 78 percent of samples were polluted.
Prihatma, head of environmental conservation at the agency, said the recent survey indicated the deteriorating condition of the city’s river system.
“Domestic waste is the major contributor of pollution,” said Prihatma, adding that E. coli
coming from human feces caused diarrhea and polluted the rivers and groundwater more than any other chemical substance, including phosphate, nitrate and ammonia.
Prihatma said it was easier to monitor the waste systems of companies, such as factories and offices, than households, where domestic waste is commonly thrown into septic tanks and rivers.
Under a gubernatorial regulation issued in 2005, households are directly responsible for properly treating their waste.
“The septic tank must not let the waste seep directly into the soil,” Rina said.
“The septic tank must be made out of water-proof materials, like fiberglass,” Rina said, adding that to reduce bacteria in domestic waste, a certain kind of capsule should be injected into the tank periodically.
She said new septic tanks were more expensive than conventional ones, but suggested residents in the same neighborhood unit share a bigger tank to reduce costs.
“We are still at the stage of introducing this concept to households,” Rina said.
“It is still very hard to implement at houses that have already been built.”
She said various programs had been imposed to encourage industrial enterprises to participate in managing their waste.
Industries located along Jakarta’s rivers are required to file regular reports on the waste management systems, which are subject to inspection every three months for a quality status.
The industries are required to sign a commitment letter stating that they will help manage their surrounding environments.
“The programs have been presented to the industries over a two-year term,” Rina said. “If they fail to comply with the programs within that term, we can shut off their waste management facilities, hampering their operations.
Rina did not elaborate on how many industries had complied with the rule so far.