As part of our water system upgrade, every water service is being equipped with a dual check valve backflow preventer. This device prevents water from flowing backward from a home or business into the city water supply, and is now required to help protect our water supply from possible contamination. After the installation of a new water service, customers may periodically notice a small amount of water being relieved from the hot water heater's relief valve. As cold water is heated it expands and must find some place to go (it can no longer flow back into the city water main). If no water is being used, this thermal expansion may increase the pressure in the water heater to a point where the relief valve will open to vent the excess pressure. Customers who experience this problem should have a plumber install a small expansion tank designed for use on hot water heaters. Failure to correct this condition could result in possible property damage and/or premature failure of your water heater's relief valve. If you have any questions, please contact the water superintendent at (410) 476-5297. E-mail: twwtp@trappemd.net