THE CHALLENGES OF WASTEWATER TREATMENT ON AN ISLAND PARADISE – THE BERMUDA EXPERIENCE

Bermuda, an island of about 60,000 residents, is located in the mid-Atlantic. The City of Hamilton is the main urban center on the island and the hub of tourist and commercial activities. The wastewater management system, originally commissioned in 1920, collects wastewater to a central point near the harbor and pumps it to the open ocean on the south coast of the island.With the aging of the existing system and the need to look at long-term wastewater management needs, the Corporation embarked on a series of oceanographic and engineering studies in the early 1990s. This resulted in the development of a two-stage wastewater treatment and disposal strategy. In the short-term, the existing comminution and pumping station would be replaced with a new wastewater treatment facility utilizing fine screening technology. In the long-term, depending upon growth and environmental impact, the strategy will see an upgrade in the level of treatment to either enhanced primary or secondary treatment and an extended, directionaldrilled outfall, that would discharge beyond the outer reef.The key objectives of the first stage were to remove floatables from the wastewater, reduce the amount of grease being discharged from the ocean outfall, and improve the overall reliability of the wastewater management system. Considering the prominent location of the new facility - literally across the street from retail shops - other key considerations included controlling odors, managing noise levels, limiting disruptions during the routine operation of the plant, and providing an architectural design that would blend the new building into the surroundings.The Front Street Wastewater Treatment Plant, commissioned in January 2002, consists of a single, multi-storied building designed in a classic Bermudian Style. Two perforated plate fine screens, with 6 mm openings, screen the wastewater coming into the treatment plant. The bagged screenings are regularly loaded onto a covered truck, within the confines of the building, and are brought to the Government of Bermuda solid waste incinerator for destruction.