Last Tuesday, July 28, 2015 a resident near the Olney Theatre Center reported sewage coming up through the ground behind their home to the Washington Suburban Sanitary Commission (WSSC). A 20 inch pressurized sewer main was leaking. It was Wednesday morning before WSSC stopped the leak and by then about 460,000 gallons of raw sewage had been spilled. Within an hour the 20 inch sew main had sprung another leak about 100 feet away and another 534,000 gallons of sewage was spilled before that leak was stopped. WSSC repair crews located the second leak and repairs to the main were completed on Thursday.
By the time the sewer main was fixed, an estimated total volume of 994,226 gallons of raw sewage wastewater had been released. A portion of the sewage flowed into Lake Hallowell and James Creek. James Creek in turn feeds the Hawlings River, which joins the Patuxent River, then flows into WSSC’s T. Howard Duckett Reservoir, popularly known as Rocky Gorge. The clean-ups at the two break sites and the nearby Olney Wastewater Pumping Station have been completed, but WSSC is closing the Browns Bridge Recreation Area for 30 days. WSSC will also increase water testing to monitor the water quality of the stream, river and reservoirs and the drinking water they deliver to almost 2 million residents of Montgomery and Prince George Counties.
WSSC is confident that sewer spill, euphemistically called an “overflow” will not affect the drinking water. The raw sewage was diluted in the streams and will be further diluted by the 4.9 billion gallons of water in the Rocky Gorge Reservoir. In addition, WSSC points out that their water treatment includes filtration and disinfection as part of the process, and water testing is conducted continuously.
This sewage spill was almost 10 times the size of the average sewage spill in 2014. In 2014, WSSC experienced 160 “overflows” resulting in 8,028,449 gallons of untreated sewage being released. According to WSSC the majority of the “overflow” volume during 2014 was caused by instrumentation/mechanical failures and excess flow. Blockages in the pipes from grease, tree roots, and debris are the leading cause of “overflows” in WSSC's system, but sewer pipe failure, though less frequent causes larger spills.
In 2005 WSSC signed a consent decree with the U.S. Environmental Protection Agency (EPA) which required the WSSC to enact a 12-year plan to reduce sewage spills. Under the agreement, the entire plan is supposed to be carried out by late 2017, with most of the pipe rehabilitation work finished by later this year. Under the consent decree, WSSC was to rehabilitate (repair and replace) 274 miles of sewer pipe. However, as of January 2015 92 miles of pipe still need to be rehabilitated. WSSC sought an extension claiming that they were behind schedule because of the permitting delays. Or possibly, they just did not apply for the permits soon enough.
WSSC provides sewer service and drinking water to about 2 million people in a 1,000-square-mile area in Montgomery and Prince George's Counties. Their service area has approximately 5,400 miles of sewer mains that need to be maintained in addition, due to continued expansion and buildout of the region WSSC adds approximately 50 miles of new mains each year.
A couple hours after repairing the sewer main, a 16-inch water main on Colesville Road at Georgia Avenue in Silver Spring broke. The 76-year-old pipe broke about 3:45 p.m. on Wednesday, and it took crews about 10 hours shut off the water, the shut-off valves were located under the water rushing from the break. Approximately 5 million gallons of water was lost. Though drinking water has been restored to all customers, work in the area will not be finished until later this week. WSSC’s contractor has been working 24 hour shifts since Wednesday.