OLNEY, MD (WUSA9) ... Officials estimate that more than 600,000 gallons of waste water has flown into the Reddy Branch Creek in Olney, Maryland since a broken sewer main was discovered Wednesday. Officials say the sewage continues to flow Thursday morning from a Sanitary Sewer Overflow. The overflow was reportedly caused by a broken 16-inch sewer main that was under pressure. According to the Washington Suburban Sanitary Commission, most of the overflow is coming from manholes near the Reddy Branch Wastewater Pumping Station in the Brookeville/Olney area. The station was reportedly shut down to relieve pressure on the sewer main, giving a better chance to repair the break. WSSC crews have reportedly found the pipe but have not yet been able to determine the exact location of the break. WSSC says the cause of the break remains unknown.