BANGOR and Holywood's sewers are set for "significant" improvement under the North Down Public Realm works.
NI Water began initial investigations into the condition of the sewers this week, in what is likely to be a six week undertaking. The majority of the work will take place at night to minimise disruption to town centre users and the company says no roads will be closed.
A spokesperson for NI Water asked parents to warn children about the dangers of playing in or near working sites.
One resident has already drawn the firm's attention to a manhole in a dangerous state in a local beauty spot.
Terry Malcolm (54) was walking his dog Jet through Linear Park, Bangor, with his two-year-old grandson Thomas, when he noticed Jet "going out of her way to avoid the manhole".
"When I got closer I knew why," he said. "It stank, there was raw sewage around it and the whole framework of the manhole had come adrift. You could see a big hole down the side."
NI Water said it was investigating how the damage occurred and warned it is an offence to tamper with manhole covers.
Terry said North Down Borough Council staff had come out on Monday and put warning tape around the manhole, but by that evening vandals had removed the safety measures.
At the time of going to press the manhole was still in a state of disrepair.
Saying his main concern is for the safety of children using the park, Terry feels that the delay in fixing the problem is "dangerous".
"If it had been out in the middle of a field a week or so would have been reasonable but I think in a park with the school holidays and it's a very well used park."
A council spokesperson said they have reported the issue to NI Water and they did tape off the area, even though it was the responsibility of NI Water.
"NI Water agreed to deal with the repair of the manhole as urgent and hoped that the work would be completed by Tuesday, August 13, at the very latest. If necessary, we will continue to lobby NI Water to seek a final resolution of this matter," they added.
A spokesperson from NI Water said they were made aware of the problem on the evening of August 7 and had been on site the same night to ensure the manhole was safe. They said staff returned on Friday morning to confirm the structure was still secure.
To report a manhole cover which has been tampered with or removed, contact Waterline on 08457 44 00 88.