7-Step Process to STP Screening
- Climate/ Regional Factors
- Stormwater Management Capability
- Community and Environmental Factors
Notes:
The matrices presented can be used to screen practices in a step-wise fashion. There are 7 steps.
Which practices are best suited for the proposed land use at this site? In this step, the designer makes an initial screen to select practices that are best suited to a particular land use.
Step 2 Physical Feasibility Factors
Are there any physical constraints at the project site that may restrict or preclude the use of a particular STP? In this step, the designer screens the STP list using Matrix No. 2 to determine if the soils, water table, drainage area, slope or head conditions present at a particular development site might limit the use of a STP. In addition, the matrix indicates which STP options work well in highly urban areas.
Step 3 Climate/ Regional Factors
Are there any regional characteristics that restrict or modify the use of certain STPs? Matrix No. 3 details potential modifications to STP selection based on climate and geology.
What watershed protection goals need to be met in the resource my site drains to? Matrix No.4 outlines STP goals and restrictions based on the resource being protected.
Step 5 Stormwater Management Capability
Can one STP meet all design criteria, or is a combination of practices needed? In this step, designers can screen the STP list using Matrix No. 5 to determine if a particular STP can meet recharge, water quality, channel protection, and flood control storage requirements. At the end of this step, the designer can screen the STP options down to a manageable number and determine if a single STP or a group of STPs are needed to meet stormwater sizing criteria at the site.
How do each of the STP options compare in terms of pollutant removal? In this step, the designer views removal of select pollutants to determine the best STP options for water quality.
Step 7 Community and Environmental Factors
Do the remaining STPs have any important community or environmental benefits or drawbacks that might influence the selection process? In this step, a matrix is used to compare the twenty STP options with regard to maintenance, habitat, community acceptance, cost and other environmental factors.