The New Castle County sanitary sewer system serves over 122,000 customers and handles 50 million gallons of water every day. The Wastewater Division designs, builds, and maintains this infrastructure as well as wastewater treatment facilities throughout the county. The system consists of approximately 45,000 manholes; 1,800 miles of sanitary sewer gravity collection system pipes ranging from 6 inches to 84 inches in diameter; 3 Wastewater Treatment Plants; and 175 pump stations.

Public Works employees are on call 24 hours a day, and their duties include everything from maintaining pumping stations, cleaning existing sewer lines, and the design and construction of new lines.