An internal investigation is underway at the Mount Hot Pools after the pools were found to be over chlorinated this morning, leaving early morning swimmers stranded for two hours.

Regular users arrived at the pools at 6am only to be informed of the glitch and were unable to use the facility until the chlorine levels were back down to adequate standards.

The Mount Hot Pools. Photo: File.

Bay Venues chief executive Gary Dawson confirms there was an operational issue relating to the chlorine pump, which lead to elevated levels of the chemical.

One pool was reopened at 7.45am and another at 8am once staff had rectified the problem. Around 20 customers were affected.

Gary says the rate of chemicals is monitored manually, rather than electronically, meaning a staff member may have forgotten to turn the tap off.

'That's really what caused the problem and obviously we don't want the pools being used when there is an issue like that,” he says.

'This doesn't happen often and we are doing an internal review to make sure we minimise the chance of it happening again.”

Among the early morning risers was Mount Maunganui resident Dave Mackay, who was told by staff that someone had forgotten to turn off the chlorine overnight.

Following a 50-minute walk to the Adams Avenue facility, Dave uses the pool three mornings a week, and says he spoke to staff again at 7am but was informed they weren't sure when the issue would be resolved

'The reason for going down early is so you don't have to trip over everybody,” he says.

'It's just the incompetence of the whole thing. It is 2015 now and if you can make Kentucky Fried Chicken with 45 different herbs and spices every time, surely you can look after a pool.

'I just think the whole thing, the management of the place in the last two years while I have been going, is lackadaisical.”