Massive swimming pool leak may portend real problems
Wednesday, November 2, 2011
The California municipal swimming pool has sprung a leak. Before the drain was plugged to prevent the major water flow, the leak appeared to have been about a million gallons in a month. Plugged, the leak has been held to 7,000 to 8,000 gallons a week. To add to the problems that may bring doubt on the future of the pool facility, the source of the leak has not been determined and recommendations have been made that the pool not be drained until the source of the leak is found.
"We want to be very sure where the leak is before we tear into the back of the building and tear out the sand filters," said Mayor Norris Gerhart. "There are a lot of options out there and we want the community to be aware some of them may not be favorable."
The pool is closed to swimmers until further notice.
At a special California City Council meeting Thursday, Oct. 27, the Board of Aldermen discussed the issue of finding the leak in the swimming pool and, if possible, repairing it.
The 1976 pool has been examined by three pool professional and two local contractors with no conclusions reached about the source of the leak or how to repair it.
One problem is that the pool is filled via direct water lines and drained via a direct main drain. One specialist was reported to have said pools are not built like this anymore. Present day pools are filled and emptied via pumps.
Kyle Wirts, Water and Wastewater Supervisor, thought it was likely the leak is in the main drain valve of the pool, but that is not certain without additional investigation. Replacement of the valve would require excavation 14 feet deep about 10 feet from the deep end of the pool and four feet from the building wall. The footing for the building is only three feet deep. It is also unknown what type of fill was used. If it was creek gravel, as is suspected, a hole with stable sides can't be dug.
According to the swimming pool professionals, the southeast area of the indoor pool has settled. Since it is not level, the water return system around the rim is not functioning as it should. The diving pool is also affected.
The leak could be in the main valve, but it may not be. The settling of the pool may have caused the leak or leaks by breaking or disconnecting main drain pipes or return pipes. On the other hand, the leaking water may have caused the settling.
It is also not clear where the leaking water is going. Some of it is draining into the ditch designed for it, but some may be in the fill material around the pool body. If water has collected around the pool, draining the pool could result in the basin rising — almost floating — because of the hydrostatic pressure. In a worst case scenario, extensive damage could result from collapse of the pool, wall and roof. Newer pools have hydrostatic valves to help prevent such a problem.
The council approved a motion to obtain several bids from professional pool companies and authorized a committee of five to select a bidder to attempt to determine the source of the leaking water and suggest a solution.
"We don't know what needs to be fixed, so we can't fix it until we know," said Wirts.
An additional expense apparently caused by the excess flow of cold water is replacement of the pool heaters. The heaters have been replaced or repaired three times since the city assumed ownership at a cost of about $25,000 each time. The heaters are in need of work again resulting in 60 degree water.
According to Recreation Supervisor Skylar Smothers, the pool drew 9,000 to 10,000 swimmers during the summer months. The fall and winter weekends generally draw a dozen or less.
A rough cost estimate given for a similar new indoor pool is in the neighborhood of $4 million.