Chief Executive John Lee and a delegation of officials and lawmakers visited a sewage treatment plant in Guangzhou on Monday as their tour of the Greater Bay Area enters its final day.

They were briefed about the operation of the various facilities, which are placed underground to reduce odour and noise.

The delegation visited Shenzhen, Dongguan and Foshan over the past three days.

When asked about her takeaways from the four-day trip, Executive Council convenor and lawmaker Regina Ip said she was impressed by the technological advancement in the various cities.

“The enterprises in mainland China could move up the technology ladder quickly because of the scale of a massive market and they made enough profit to do more R&D,” she said

“So for Hong Kong to jumpstart our tech development, we need to partner with the mainland.”

The group will meet with Guangdong officials in the afternoon before returning to the SAR.