SEPTA is working to control water leakage into the subway at Eighth and Market Streets. The project began in January of this year and is almost completed.Saws whined as construction workers cut away pitted old concrete to get at the steel beams beneath. Three blue trash pails caught water streaming from the ceiling on Wednesday as rain pounded the city above.
“We’re down to a couple of buckets,” said Kyle Stevens, a senior project manager who supervises the and Market Street work. He said the rain had an upside: “It helps us find problem spots that are left and target them.”SEPTA moved to do the waterproofing project as water infiltration increased over the years and it became harder to keep up with spot repairs.
To coat the tunnels, the crews build a layer cake of waterproofing: bituminous material ; a special kind of cement; Sika, a powerful adhesive and sealant that costs $145 a square foot, and corrugated plastic.“It travels just like water, and it reacts to water,” said Chris Hopkins, a consultant to SEPTA on the project from engineering firm Michael Baker International. “You can see this colored fluid and it seizes up all of a sudden” and plugs a problem spot.almost done, Stevens said.
Eighth and Market station in about a year is “no small task,” Hopkins said, adding that similar jobs can take two years in some cases.