For the second year in a row, part of a lake in the retirement community of Bella Vista is closed to swimming and wading because of high levels of E. coli bacteria. Signs have been posted on Lake Avalon from the west shoreline to the lake`s first no-wake buoy. No contact with the water will be allowed at the boat launch ramp and the boat mooring section out to the no-wake buoy. High levels of E. coli bacteria were detected in the lake July 24th. Officials have not determined the source of the contamination. All other areas of the lake, along with other lakes, have been tested and found to be normal. Last year, fecal coliform was found in both Lake Avalon and Lake Windsor with levels six to seven times the state standard. Both Lake Brittany and Lake Norwood also exceeded the acceptable level of fecal coliform contamination.