THE VIRGINIAN-PILOT
Copyright (c) 1996, Landmark Communications, Inc.
DATE: Thursday, October 31, 1996 TAG: 9610310311
SECTION: LOCAL PAGE: B2 EDITION: FINAL
SOURCE: BY MEREDITH COHN, STAFF WRITER
DATELINE: CHESAPEAKE LENGTH: 77 lines
Internal corrosion was the cause of a pipe break about three weeks ago that sent thousands of gallons of raw sewage through a Deep Creek neighborhood, sanitation workers have determined.
Investigators said they are still testing other areas of the Chesapeake system in an effort to find worn segments before they burst.
Employees of the Hampton Roads Sanitation District, which maintains the region's pipes, should know in a week or two which sections will need work. In the meantime, city health officials say, it is no longer dangerous to walk outdoors or fish in Deep Creek.
Internal deterioration happens when air gets into the pipe, combines with hydrogen sulfide from waste water and creates sulfuric acid. The acid eats away at the pipe, said James R. Borberg, the sanitation district's general manager.
``We try to periodically bleed this gas off so there is no acid creation,'' he said. ``But there are some parts of the pipe we can't get at.''
The part of the pipe that burst at the corner of Winslow Avenue and Woodbriar Lane in the Forest Cove neighborhood Oct. 9 was a high point in the system where acid collected. Unlike most high points, the area was not equipped with a vent, Borberg said.
The city is now using ultrasonic meters that use sound waves to determine the thickness of the pipes. Workers have been keeping pressure low in the Deep Creek area to avoid other breaks while the work is done.
``We've gotten a few thousand feet away from where the break was,'' he said. ``We're surveying the entire area to see the extent of the problems. Then we will determine how to repair the damage, depending on the length of deterioration and where the pipe is.''
Sanitation district workers are trying to avoid digging up pipes in residents' yards by lining them with fiberglass tubing or relocating them.
Residents reported no health problems, and Deep Creek, a tributary of the Elizabeth River located close to the spill, suffered no significant effects from the sewage, according to the Chesapeake Health Department and state Department of Environmental Quality.
Meanwhile, life is getting back to normal for families forced out of their homes by the sewage spill. The sanitation district is paying for cleaning and repairs to sheds, fences and outdoor equipment, and indoor walls, floors and appliances.
The Chesapeake Health Department's warning to wash hands, hose down pets and avoid walking through yards is no longer necessary, said Jeff Goodchild, the environmental health manager.
But Goodchild added that homeowners around the city with septic systems could face similar risks if their systems fail.
Chesapeake lies in a coastal plain and, depending on soil conditions, if the water table rises too high - usually in winter and early spring - some older systems may malfunction and send raw sewage to the surface.
The first sign residents may notice when the system is failing is slow toilet drainage, Goodchild said. Eventually the water will not go down and the lines carrying sewage to be treated may need to be replaced.
The average life of a septic system is 10 to 15 years.
``People only have to take precautions if they have malfunctioning septic systems,'' he said.
However, Frank Frye, a Western Branch resident who uses a septic system, said he wanted to pass on ``neighborly advice'' to check the yard before sending children outside.
``Within a month of installing my new system, water began to bubble up in the yard,'' he said. ``There's no avoiding it when the drain fields are below the water table.''
Across town, in unrelated sewer pipe testing, the Public Utilities Department is sending smoke through the system to check for leaks that allow rainwater in and sewage out. Residents along Kempsville Road between Battlefield Boulevard and the Virginia Beach line may notice smoke coming from plumbing vents on their roofs or area manholes.
The smoke is not dangerous, said John Knowles, the wastewater reliability superintendent.
Knowles asked that citizens call 382-8475 if they have questions or concerns about the testing.
KEYWORDS: SEWAGE SPILL by CNB