A Taiwanese plating company in the northern province of Bac Ninh was caught illegally discharging untreated wastewater into a local rainwater pipeline Friday.
Environmental crime investigators from Bac Ninh and the Ministry of Public Security discovered the secret pipes hidden underground.
The pipes have been transporting dangerous waste from the LongTech Precision Vietnam Company's plating room into the rainwater pipeline of Que Vo Industrial Zone, according to local news website VnExpress.
The discovery was made after the team of inspectors had monitored the site for several days, the VnExpress story reported.
The wastewater was dark green with a lot of oil and scum, a report by the Dan Tri newswire said. The zone's rainwater pipeline flows into a local river.
Danny Liao, general director of the company, conceded that the investigators discoveries and conclusions appeared correct.
But he also said that he and other company leaders had been unaware of the system, stating that lower-level employees had carried out everything on their own.
The director said the plating room discharges around 100 cubic meters of wastewater every day.
Police have asked the company to dig up parts of the concealed pipeline for investigation.
During the inspection, the factory, which opened in 2006, was also found mixing toxic waste with non-toxic waste and violating other environment regulations, according to police reports that did not specify the other violations.