The court also found that the Pollution Control Department (PCD) had ignored its duties in enforcing pollution-control laws on the BMTA and had failed to monitor the agency even though the Central Administrative Court had ordered it to improve bus services and ensure they met requirements under the environmental protection law.
It ordered the PCD to rigidly enforce the law, ensure full supervision of the BMTA and report the results of emission tests every three months to the court for a year.
Thursday’s ruling comes after 12 years of legal wrangling in one of the most protracted court battles concerning environmental issues.
In 2002, Foundation for Anti-Air Pollution and Environmental Protection and a group of Bangkok citizens filed four lawsuits with the Central Administrative Court against the BMTA — the city's bus operator — and the PCD for failing to tackle foul black smoke emitted by city buses. The court combined the four suits into one.
The court ruled in 2006 that the BMTA was guilty of failing to provide acceptable public buses. The BMTA operated more than 14,700 buses, but had only 33 pollution inspection machines, not nearly enough to properly test all of its vehicles.
The court ordered the bus operator to improve engine maintenance across its fleet.