An analysis of the waterproof paint finish to the concrete pool basins is being carried out by research organisation BRE. According to Bath & North East Somerset council, the client for the project, the paint surfaces bubbled when the pools were filled with water from a thermal spring.
A council spokesperson said: "We are not achieving the quality finish everybody intended. If we're going to repaint the pools, we need to work out what the issue is, and we don't know when we are going to come to a conclusion."
One possible cause of the problem is a chemical reaction between the paint and the minerals in the warm thermal spring water.
Other problems to the project have included a legal dispute over the impact of the project on the city's spring waters and delayed tests on the hot springs caused by mating mallards.