DGS staff member A. Scott Andres made a presentation “Results of selected UD nutrient monitoring projects in the Nanticoke River watershed” at the inter-agency meeting Chesapeake basin water quality data, trends, and interpretations held August 11, 2016 at the Delaware Department of Agriculture in Dover.
The long-term performance of rapid infiltration basin systems (RIBS) and their potential impacts on the receiving environment have been previously unknown for Delaware. A variety of field experiments were conducted to characterize the geology and hydrogeology of a RIBS facility that has been in operation for more than 20 years at Cape Henlopen State Park. Pairs of standard monitoring wells and short-screened multi-level wells were used to evaluate the significance of small-scale vertical variability in water quality.
The Delaware Geological Survey released a new technical report entitled “Groundwater Quality and Monitoring of Rapid Infiltration Basin Systems, Theory and Field Experiments at Cape Henlopen State Park, Delaware” which was prepared by A. Scott Andres and Changming He of the Delaware Geological Survey, Edward Walther of the South Water Management District, Florida, Müserref Türkmen of the Izmir Water and Sewerage Administration, Turkey, and Anastasia Chirnside and William Ritter of the University of Delaware. DGS Bulletin 21C documents the results of a detailed study of groundwater quality at a rapid infiltration basin system.
A rapid infiltration basin system (RIBS) consists of several simple and relatively standard technologies; collection and conveyance of wastewater, treatment, and discharge to an unlined excavated or constructed basin. By design, the effluent quickly infiltrates through the unsaturated or vadose zone to the water table. During infiltration, some contaminants may be treated by biological and/or geochemical processes and diluted by dispersion and diffusion.
This technical report evaluates several aspects of potential environmental risks, use, and regulation of rapid infiltration basin systems (RIBS) in Delaware. The report reviews and compares regulations regarding RIBS from Delaware, Florida,North Carolina, New Jersey, Maryland, and Massachusetts. Influent and effluent samples from ten advanced wastewater treatment systems that operate in conjunction with RIBS were collected and analyzed.