Each spring, large quantities of dissolved nutrients (such as nitrogen and phosphorous) are transported from the upper Midwest into what is called the Gulf of Mexico Dead Zone — an oxygen-deficient area that grows to approximately 8,000 square miles each year and cannot support marine life.
In Chicago, the public right of way includes more than 4,000 miles of streets and 2,100 miles of alleys — paved impermeable surfaces that contribute significantly to urban runoff that eventually makes its way to the Gulf.
The Chicago DOT (CDOT) is addressing this problem with a comprehensive sustainable streetscape project that will use several environmentally friendly techniques commonly associated with LEED-certified buildings but not typical in streetscape designs. The department will evaluate the techniques to assess their suitability for future projects and create a model for watershed planning in the combined sewer area.
Construction is scheduled to begin in late 2009. It is funded largely through a tax increment financing district, but it has also received several grants, including nearly $450,000 through the Illinois EPA 319 nonpoint source pollution program (which funds best management practices such as rain gardens, permeable pavers, and bioswales) and $73,200 from the Federal Highway Administration's Ecological Grant Program in addition to in-kind services from the Metropolitan Water Reclamation District of Greater Chicago.
The project, designed and implemented by AEC firms Wight & Co. and Knight E/A, is located on the city's near south side along two major arterials — Cermak Road and Blue Island Avenue between Halsted Street and Western Avenue.
Cermak Road is a five-lane truck route with no on-street parking and 10- to 15-foot-wide parkways. It divides the Pilsen neighborhood from an industrial district along the south branch of the Chicago River.
Blue Island Avenue is a five-lane truck route with street parking and 20-foot-wide parkways just north of the project area.
The project began when CDOT set out to determine what the equivalent of a platinum-rated streetscape might look like and what environmental, cultural, and economic benefits it may provide. The platinum rating is the highest level of achievement awarded by the U.S. Green Building Council (USGBC) for a project's level of commitment to sustainability. Wight and Knight developed a series of environmental categories and identified goals similar to a LEED scorecard:
Recycled Content. Recycle at least 90% of construction waste (excluding landscape debris) based on total weight or volume similar to the USGBC's LEED-NC criteria. The sum of post-consumer recycled content plus one-half of the pre-consumer content must constitute at least 20% (based on cost) of the total value of the materials in the project.
Energy Conservation. Reduce energy use by a minimum of 40% below the streetscape baseline typical of new construction; use reflective surfaces on sidewalks/roadways; use dark-sky-friendly fixtures. Use materials or products that have been extracted, harvested, or recovered, as well as manufactured, within 500 miles of the project site for a minimum of 40% (based on cost) of the total materials value similar to LEED-NC criteria.