PURCELLVILLE, Va. October 14, 2016— During routine inspections on the morning of Friday, October 14th, Town staff at the Basham Simms Wastewater Facility (BSWF) identified an indication of chlorine in the effluent, the treated water which is discharged into a local stream. Upon further review, the water sampling analyzer indicated that an excess amount of chlorine had been discharged in the system the prior day, October 13th.
An analysis of the BSWF computer system and staff activities has identified that during a routine cleaning process of the membrane filters, chlorine used to disinfect the membrane filters was inadvertently allowed to enter a holding tank and then was discharged with the remainder of the effluent. It is important to note that chlorine is not used in the regular wastewater treatment process; instead, the Town uses an ultraviolet (UV) disinfection process. The introduction of chlorine was only a result of the cleaning of the membrane filters.
The amount of chlorine released, while higher than levels typically permitted in discharged water, did not present a threat to the public, as it was diluted with other effluent and through natural diffusion. However, upon visual inspection, staff did note a small number of minnows that were deceased, likely due to being located at the immediate point of discharge and due to the level of chlorine at that location. Staff have taken additional samples at the point of stream entry to confirm there are no detectable levels of chlorine at our point of discharge or in the stream pool.
Town staff have been coordinating with the Virginia Department of Environmental Quality (DEQ) and the Fire Marshal’s Office regarding this event. All corrective action has taken place.
As a result of this incident, staff at the BSWF will be reviewing and revising procedures to ensure that such incidents do not happen in the future.