Skip to main content

PHILADELPHIA'S STORM WATER AND CSO PROGRAMS: PUTTING GREEN FIRST

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

Philiadelphia Water Department (PWD) is striving to re-invent the traditional Combined Sewer Overflow (CSO) control program. Instead of focusing on grey infrastructure (increased conveyance and storage capacity followed by treatment) with source controls added to further reduce CSOs, PWD is exploring the feasibility of making green infrastructure the primary contol measure, with grey infrastructure added only where required. That a green approach can be theoretically effective has been shown by extensive model simulations. Simulations show that the uncontrolled runoff, much of which becomes CSOs, can be reduced by more than 90% if all impervious surfaces are retrofitted. This would, however, require a complete retrofit of streets, parking lots and roof connections over a 20 to 30 year period. Although a great deal of this conversion could be accomplished as the City redevelops and renovates through enforcement of the newly instituted storm water regulations, it would also require a significant “economic push” through planned retrofits, aggressive storm water rates tied to impervious cover, and other incentives. This suggests that a careful weighing of costs associated with green infrastructure vs “grey infrastructure” is needed before the appropriate balance between green and grey is found.

Although initial cost estimates suggest that green infrastructure may result in slightly higher unit costs per gallon storm water captured than the lowest cost grey infrastructure alternative (current planning level estimates suggest an average cost of approximately 4 – 6 per gallon), this does not include the numerous other benefits associated with green infrastructure. With the considerable benefits associated with the green approach to storm water and CSO controls, Philadelphia is looking at setting a preliminary target for applying green storm water controls of between 50% and 60% of all impervious cover in the city. If this number can be achieved within a 20 to 30 year time frame, many of the costs required to increase storm water conveyance and storage facilities can be largely avoided and the city's urban environment will benefit.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2008-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more