UV Treatment Upgrades In Wales

Swansea Bay is located on the Bristol Channel on the southern coast of Wales and is home to the Swansea Wastewater Treatment Works (WwTW). Swansea WwTW is operated by Dŵr Cymru Welsh Water and is a key treatment plant because Swansea Bay is designated as bathing water. In the late 20th century Swansea Bay was prone to pollution problems, primarily because of a poorly sited main sewer at Mumbles Head, which screened and stored sewage in four underground tanks before releasing it back down the outfall on the ebb tide. Swansea Bay is home to one of the highest tidal ranges in the world and at low tide the sea retreats so far from the high tide marks that it exposes remnants of a prehistoric forest. As a result, the natural current in Swansea Bay often didn’t transport the polluted water far enough out to sea, and recirculated it instead around the Bay and then down the Bristol Channel.

In the late 1990s, construction was completed on a wastewater treatment plant near Port Tennant, and was considered at that time to be one of the most technologically advanced wastewater treatment plants in the world. The Swansea WwTW is buried underground with extensive landscaping making it practically undetectable from inland. It was originally designed to treat wastewater for a population equivalent (PE) of 165,000, but currently treats wastewater for a PE of approximately 185,000. The Swansea WwTW treats water from the Swansea Valley and eastern and central areas of the city.

In order to improve the treatment performance (because of the continued cost to maintain compliance), and ensure that it would eventually have the treatment capacity to meet future population growth equivalent of up to 225,000, Swansea WwTW was in need of an equipment upgrade. This would replace the previously installed TrojanUV4000®, which was configured as Duty/Assist. That system contained two banks, each with five UV modules with 16 lamps per (eight lamps deep and two lamps wide).