Lotte Group said on Monday that it asked two organizations to investigate safety problems at the second Lotte World and the areas in its vicinity where it is being constructed in Jamsil, southern Seoul. The probe request comes on the back of mounting concerns about nagging environmental problems.

Lotte Engineering and Construction said it has commissioned the Korean Geotechnical Society and U.K. engineering firm Ove Arup to look into safety matters in connection to recent allegations that the construction of the 123-story tower has led to sudden environmental changes in the area.

Earlier this month, an advisory committee comprised of Seoul City officials and other experts found that the construction of the second Lotte World may be the cause of the falling water level of nearby Seokchon Lake.

The discovery came after other environmental experts claimed that the water level of the lake had been sliding since the first phase of underground excavation work for the building was completed in 2011.

Some believe that the construction of the 555-meter-tall tower is responsible for creating sinkholes ― holes in the ground caused by some form of collapse of the surface layer ― due to its excessive excavation.

“Over the next four months, Ove Arup, which participated in the building’s civil engineering design, will look into environmental changes including those on the surface level, while the Korean Geotechnical Society will investigate the cause of the water-level change,” an official at Lotte Group said.

Currently under construction, the second Lotte World complex will consist of four buildings ― the 123-floor Lotte World Tower, an eight-floor department store and two 11-floor commercial buildings.

Last month, Lotte Group submitted an application to Seoul City for the green light to open the three low-rise business malls ― which will house an entertainment complex, a department store and shopping mall.

The group’s initial plan to open them in May has been much delayed, as Seoul City is dragging out the process to review the application. Normally, permission is given in just weeks.

Along with the environmental concerns, the second Lotte World is also facing steep criticism for causing several accidents, which left two construction workers dead at the site and six others injured. The complex is also expected to cause traffic congestion in the area as the three lower buildings are estimated to attract up to 200,000 people a day.

Seoul Mayor Park Won-soon has taken a strong stance against such problems, saying that there will be “no approval” unless safety is ensured. The city government reportedly asked Lotte Group to correct the safety problems and resubmit the application for permission to open the facilities.

During a separate site tour of the second Lotte World, Park had said he would “never condone anything that threatens the safety of citizens.”

By Park Han-na (hnpark@heraldcorp.com)