The Philadelphia Water Department (PWD), starting July 1, 2010, will begin charging landowners a Stormwater Management Service Charge, as a separate component of a landowners water bill. The charge will be based upon a formula that relates Impervious Area to Gross Area of a parcel of land in Philadelphia.
Philadelphia has a "combined sewer system" and as such, when it rains there is an overload on the sanitary sewer system caused by the large volume of stormwater that enters the system. The goal of the Stormwater Management Service Charge is to bring attention to the landowner of the true burden that its property is placing upon the sanitary sewer system. The inflow and infiltration of stormwater into the "combined sewer system" creates a situation which must be addressed by providing incentives to landowners to retrofit their properties with stormwater management and treatment BMPs that will reduce the volume of stormwater that leaves the property and enters the " combined sewer system".
While the Stormwater Management Service Charge will result in an increase in fees for the PWD, the long term objective must be stormwater runoff volume reduction. The increase in fees generated, no matter how significant they may appear, is not a long term solution. The long term solution requires a systemic change in the way a landowner manages stormwater runoff generated by a particular parcel of land based upon its impervious area.
Previously, a landowners water bill was based upon the type and size of the water service provided to a parcel by PWD.
This charge will begin on July 1, 2010 and will be phased in over over time. It is expected that there will be a dramatic increase in the charges and fees payable to the PWD based upon the Impervious Area calculations.
Terre Hill Stormwater Systems designs, engineers, manufactures, installs and maintains stormwater manufactured BMPs constructed out of precast concrete.
The Terre Kleen is a hydrodynamic separator that removes oil, grease, trash, debris and sediment form stormwater runoff. The Terre Kleen is best used as a pretreatment BMP, which enhances and protects the function of other BMPs in the treatment train. For example, a Terre Kleen placed before an infiltration system prevents pollutants such as trash, debris, oil, grease and sediment from entering the infiltration bed and causing a build up of pollutants which impair the functionality of the system.
Terre Hill Stormwater Systems also manufactures the Terre Arch. The Terre Arch is a precast concrete multi roman arched structure that is ideally suited for urban environments. It is HS-25 load rated and thus, facilitates the use of all surface land area.
Developed parcels in Philadelphia can benefit from the use of a Terre Kleen and/or Terre Arch in applying for Stormwater Management Service Charge Credits and Adjustments.
The Impervious Area Stormwater Credit (IA) requires that the landowner collect and treat and manage the 1st 1" of rainfall. There is no "partial credit" for less than 1" of collection and treatment. The goal of volume reduction set by PWD requires the landowner reduce the runoff from the parcel for the entire 1st 1" of rainfall. The Terre Arch provides a solution which will allow the landowner to continue to use the entire surface area of the parcel and also qualify for the IA Stormwater Credit.
The Gross Area Stormwater Area (GA) requires a landowner to attenuate the peak flow so that the NRCS-CN is equl to or less than 86. For each number reduction below 87 a landowner will receive a 7% reduction in its Stormwater Management Service Charge up to a 100% credit. Terre Hill Stormwater Systems manufactures the Terre Box with a watertight joint seal system which will allow the landowner to reduce the NRCS-CN to 86 or below and still utilize the entire surface area because of the HS-25 load rating of the Terre Box structure.
Placement of a Terre Kleen in front of the Terre Arch retrofit will protect and enhance the life cycle of the Terre Arch infiltration System and will reduce maintenance costs for the system.
Terre Hill Stormwater Systems can provide valuable design, engineering and structures for PWD customers to provide a solution that benefits both the customer and PWD, by reducing stormwater runoff volume and reducing Stormwater Management Service Charges.
Please contact Terre Hill Stormwater Systems
www.terrestorm.com, 1 800 242 1509 or 717 445 3100.
