SLRWD mordernises Waste District Wastewater Treatment Plant in Angola SLRWD mordernises Waste District Wastewater Treatment Plant in Angola Modified date: The Steuben Lakes Regional Waste District (SLRWD) has modernised the Waste District Wastewater Treatment Plant in Angola. The SLRWD has installed new filters in the plant to improve its operation to 9,092.18 m3 per day. The SLRWD has also equipped the plant with a “more efficient filtering system that is less sensitive to weather-related disturbances The new filter system installed at the Waste District’s wastewater treatment plant uses a fabric media suspended on large rotating discs. These allow the plant to filter and remove all solids from the wastewater that has been treated and is ready to leave the plant.