Tidewater Environmental Services, TESI, owns and operates several wastewater facilities. Operational since 2004, it serves more than 30,000 customers. Tidewater Environmental Services is a subsidiary of Tidewater Utilities, which supplies water on a retail basis for over 410 residential communities in Delaware. Tidewater Utilities offers a range of water and wastewater services, such as consulting, contract operations, maintenance and bulk water supply. It operates 24 hours a day, seven days a week. The company ensures compliance with the Delaware Health and Social Services Division of Public Health s standards. It also operates White Marsh Environmental Systems, which offers system design, waste hauling and stormwater management services. Tidewater Utilities is a part of Middlesex Water Company.