With the clock ticking on the federal mandate for Pittsburgh to fix its nagging storm water problem, a handpicked group of experts has focused on the South Side for new ways of keeping sewage out of the rivers.
More than 60 engineers, landscape architects, environmental scientists and planners volunteered last week for the three-day "South Side Green Infrastructure Charrette" and targeted the old Birmingham neighborhood.
The Brew House Association, an artists' collective located at the former Duquesne Brewing Co. building on South 21st Street, provided free use of its ground floor for the project, and 19 companies sponsored the event, including the Allegheny County Sanitary Authority, Pittsburgh Water & Sewer Authority and UPMC.
Whatever is learned by controlling storm water runoff along the half-mile strip of South 21st Street, from South Side Park to the Monongahela River, could be applied to neighborhoods throughout the city.
"This is the first time we've done an exercise like this with a specific boundary," said Joel Perkovich, a sustainable design manager at Studio Phipps and event chairman at the Green Infrastructure Network, the group that organized the design exercise.
The central issue of the event was storm water runoff. When it storms in Pittsburgh, rainwater flows into sanitary sewers, overflowing pipes and spilling raw sewage into the rivers at the rate of approximately 1 billion gallons per year. The sewage outflow is in violation of the federal Clean Water Act.
In 2008, the Environmental Protection Agency gave Alcosan until 2026 to fix its problem. In January, the EPA rejected Alcosan's proposal, leaving the authority searching for solutions.
The proposals put forth by the green network could be just what Alcosan and the EPA are looking for.
Mr. Perkovich hopes that "green infrastructure" will be part of those solutions and wants to use South 21st Street as an example of how Pittsburgh could keep rainwater out of the sewer system while also beautifying the city and improving residents' quality of life.
Currently, storm water gets routed into bigger and then bigger pipes, where it either spills into the river or reaches the Alcosan sewage treatment facility.
Instead of allowing that water flow to Alcosan, Mr. Perkovich wants to capture rainwater close to where it lands. By installing "pervious landscapes" -- a combination of soil, vegetation and water-soluble hardtop surfaces -- he believes most rainwater could be kept out of the sewers, decreasing the flow to Alcosan.
Brad Palmisiano, an engineer, and his design team observed that ground water from naturally occurring springs at South Side Park currently flows directly into a sewer catch basin.
His team envisioned a South Side Park where pervious landscapes put water back into the ground.
"The big-picture goal is to capture the volume produced by the 1-inch storm event and reduce pollution that would otherwise be overflowing into the river," said Joe Fello, a civil engineer with GAI Consultants, who participated in the design session. Mr. Fello said that green infrastructure would beautify the city, as well as reduce flooding.
Mr. Fello worked on a design team that looked at the section of South 21st Street near UPMC Mercy's South Side Outpatient Center, a part of the street that includes median parking spaces where trolley tracks once ran. Mr. Fello and his team propose redesigning the street, replacing some of those parking spaces with green space that would absorb water.
"The area would be permit-parking only, for residents," said Frank Dawson, a landscape architect. Mr. Dawson said that parking is always a concern, but he believed 70 percent of the spaces could be retained.
Greg Scott, an engineer, worked on an alternate design for that section of South 21st Street. His team would remove the parking spaces altogether and redesign the road so that it zig-zags, with alternating fields of green space on each side of the road. Mr. Scott said this would calm traffic, add public space, and give some residents a front yard of sorts.
Lisa Hollingsworth-Segedy, an associate director at American Rivers, went door-to-door around South 21st Street, talking with residents, and said that any good design must involve the community.
"We can sit here and draw these plans, but it's not going to happen if it's not what the community needs," she said.
For Matt Graham, a founding partner of Landbase Systems with a background in landscape architecture, green infrastructure is also a better way to spend money from utility fees.
"If we've taken water out of the gray-water system and put it on green, it's one more gallon we don't have to treat," said Mr. Graham. "Spend the money on maintenance rather than gray-water treatment."
Correction, posted April 14: An earlier version of this article referred to storm water runoff flowing into the Allegheny River; this has been corrected to change that reference to the Monongahela River.
Brett Sholtis: firstname.lastname@example.org and 412-263-1581.