Failing aerobic treatment unit and direct discharge system repaired UV unit
Problem: An existing direct discharge system was designed to provide secondary treatment for two properties on Woolens Lane in Culpeper, Virginia, but was out of compliance and did not meet the state’s discharge limits.
Solution: Tom Basham at Nokesville Design designed an EZ Treat Model 600 unit with a Model #102 UV Unit to bring the discharge system into compliance with the Virginia Sewage Handling and Disposal Regulations and the DEQ. The existing septic tank and ATU was pumped and abandoned in place. The new design will consist of a Hanover Precast 1,500-gallon baffled septic/recirculation tank, an EZ Treat Model 600 treatment unit and an EZ Treat Model #102 UV unit for disinfection and a Hanover Precast 2,000-gallon pump chamber. This plan was designed to meet the Class I reliability standards. Accordingly, the pump chamber had storage capacity of more than 100% of the forward flow above the alarm float. A Fralo monster box with an aeration stone was installed prior to the discharge point. The unit is designed and approved to treat hydraulic flows up to 600 gpd, producing advanced, secondary quality of treated effluent and is a Generally Approved TL-3 (Treatment Level) system in Virginia. In Virginia, TL-3 effluent requirements mandate the treated effluent to have a five-day BOD and TSS of 10 mg/L or less. The Model #102 UV unit is a gravity-fed, dual-bulb device capable of treating a maximum flow rate of 10 gpm.
Result: The units solved these difficult site conditions that required advanced, secondary quality of treated effluent limits. 703-753-4770; www.eztreat.net
