Mr Bernard Koh, PUB' s director for  water supply plants, welcomed  Tuaspring' s workers at a gathering on Tuesday (May 21) morning, and said: " Today is the first working day, even though we took over the plant on May 18.  Now you are part of the PUB team. You have only one mission, and that' s very clear - supply good water...  I believe we have a very good team here... This plant needs upgrading works, replacement work. You know the condition. Let' s work together and restore it to the full 70 million gallons per day (mgd)."

The  transfer from embattled water treatment firm Hyflux  took place following the termination of the water purchase agreement with Tuaspring on May 17. The desalination facility is part of the Tuaspring Integrated Water and Power Plant that cost Hyflux $1.05 billion.

The water contract stipulates that  Tuaspring is required to deliver up to 70 mgd in desalinated water to PUB over 25 years -    from 2013 to 2038. Its plant capacity is equivalent to 16 per cent of Singapore' s daily water demand of 430  mgd.

But the plant has had operational issues since early 2017, and Hyflux lacked the funds to resolve these issues. It has been unable to replace poor-performing membranes in its ultra-filtration and reverse osmosis systems promptly, which affected the quantity and quality of the water produced. It has also failed to supply PUB with 70 mgd of desalinated water on numerous occasions.

Mr Koh, speaking to  reporters on Tuesday morning, said: " Membranes replacement is necessary to ensure that plant capacity remains at designed capacity...  Certain membranes need to be cleaned regularly. If not maintained, their performance will deteriorate faster...  The default was that the concession company was unable to deliver the required capacity when needed." He declined to give details of the production shortfall.

What needs to be replaced are membranes within 72 ultra filtration trains or racks, which are part of Tuaspring' s pre-treatment filtration system to remove sediment and suspended solids 17 high-pressure reverse osmosis  trains, where most of the salt and minerals are filtered out, and nine low-pressure reverse osmosis trains, he added.

" When the membranes have been replaced, we can bring (the plant' s water output) back up to 70 mgd," Mr Koh said.

He declined to disclose how much it would cost and how long it will take to replace the membranes.

To facilitate a smooth transition, PUB conducted several dialogue sessions with the plant' s existing staff about a month ago, prior to the takeover, and explained to them their employment terms and conditions.

Said Mr Koh: " Our priority was to ensure the staff joined us to facilitate the continuation of operations. That was done successfully."

About 90 per cent or 36 staffers were re-employed by PUB under what Mr Koh described as a " no worse-off basis" conditions. Most of the staff' s concerns had been over their terms of employment, including bonuses and other benefits.

" They were pleased and relieved they were not worse off," Mr Koh added.

In addition, three PUB employees with experience in operations and maintenance of desalination plants, were posted to Tuaspring to help with the transition.

Ms Hamidah Mohd Razak, a senior quality environmental, health and safety manager who has  been with Hyflux since October 2018, said: " There was a lot of uncertainty initially...  Our biggest concern was job security. We were worried where could we go after this. Now that it' s cleared up, it' s a fresh change for all of us."

On her employment terms and benefits, Ms Hamidah, 37, said: " That' s the best part. It stays as it is. I' m quite grateful for it because a lot of people were worried over whether there will be salary cuts. So far, there are no changes. Even our leave entitlement  is getting better."