"We need to better integrate the work of state agencies which are in charge of enforcing 12 laws relating to waste management. The Interior Ministry, provincial governors and local administrations should be the focal points in dealing with rubbish management," she said.
Ms Yingluck Monday went to the fire-gutted rubbish dump in tambon Phraeksa in Samut Prakan's Muang district to inspect the situation there. She also chaired a meeting of relevant authorities about the environmental and health impacts of the landfills.
The blaze and related pollution problem were solved quickly due to the cooperation of agencies concerned, she said.
The fire at the dump was put out on Saturday night, after burning for six days.
Officials from the province, however, must work with the local administrators to work out plans to prevent such fires breaking out again, she said.
According to the prime minister, the Pollution Control Department has tested the air quality at the landfill and in nearby areas and it has returned to normal levels.
Despite the smell, the areas are regarded as safe, she said.
Samut Prakan governor Kanit Iamrahong said residents who were earlier evacuated due to the pollution caused by the blaze have now returned home.
Meanwhile, environmental activists Monday urged government agencies to take legal action against the people linked to the Phraeksa rubbish dump fire and pollution.
"Our society has rarely taken serious legal action against polluters who must be held responsible for causing harm to the environment and people's health," said Ecological Alert and Recovery Thailand director Penchom Saetang.
Ms Penchom said her team inspected rubbish management sites in Samut Prakan province over the weekend and found at least two dumps were still being operated despite locals complaining about the bad smell and poor management.
"Local authorities have taken some action over the years to relieve problems following locals' complaints. But authorities still can't stop the dumping of hazardous waste," said Miss Penchome.
"Illegal rubbish dumping is a large business which involves local mafia gangs and corruption that stops us from solving its problems."
Arpa Wangkiat, a professor at Rangsit University's environmental engineering department, said authorities often imposed light penalties against culprits in past illegal waste-dumping cases.
"Pollution makers must compensate for damages, and also carry out a clean-up process to heal the environment and people's health," she said.
The Industry Ministry, which directly enforces the law for industrial waste management, must inspect other garbage dumps to see if there is any hazardous industrial waste, she said.
Somnuek Jongmeewasin, an independent researcher on the environment and community services, said more industrial plants have emerged even though Thailand does not have enough waste-processing facilities.
More than 16,000 factories produce hazardous industrial waste, but the country has less than 20 legal waste processors.