however, specifically required that states earmark 20 1 % of their State Revolving Loan Fund (SRF)
2 capitalization grants for innovative stormwater management practices such as green infrastructure, in
3 addition to energy and water conservation initiatives (the Green Project Reserve). This requirement also
4 applies to the FY10 regular SRF capitalization grant. Both ARRA and the FY10 regular SRF program
5 also required states to provide a portion of their total SRF assistance in the form of subsidization
6 (principal forgiveness or grants). Counties and municipalities qualifying for principal forgiveness could
7 easily apply these more favorable funding terms to their green infrastructure projects
9 Notwithstanding the financial incentives provided by the Green Project Reserve, cost-effectiveness is one
10 of the driving forces behind the increasing, widespread national adoption of green infrastructure practices.
11 In general, national and Illinois examples indicate that properly scaled and sited green infrastructure can
12 deliver equivalent hydrological management of runoff as conventional stormwater infrastructure at
13 comparable or lower costs than conventional conveyance and treatment infrastructure. Moreover, green
14 infrastructure also delivers additional economic, social and ecological benefits that are normally not
15 monetized, contributing value to community health and vitality beyond their hydrologic performance.
17 When green infrastructure performance for volume control and water quality can offset regulatory
18 requirements, i.e., when using green infrastructure counts as a credit against detention volume
19 requirements, scenarios that evaluate green infrastructure life cycle costs also demonstrate savings in
20 comparison to equivalent conventional infrastructure. For example, Table ES-2 below shows estimated
21 costs and hydrological results of three development scenarios (a suburban subdivision, an urban
22 townhouse project, and a commercial building) using CNT‘s Green Values® Calculator.
24 IV. CURRENT PRACTICES
26 We reviewed three types of current stormwater regulatory programs with performance standards
27 incorporating green infrastructure concepts. First, we reviewed the Illinois statewide stormwater permit,
28 known as the MS4 Permit. Second, we reviewed existing county and municipal stormwater management
29 ordinances in Northeastern Illinois, the region with the greatest experience in using green infrastructure.
30 Finally, we reviewed five state programs outside Illinois that have in place statewide stormwater
31 management performance standards that expressly encourage or require the use of green infrastructure as
32 a means of meeting those standards.
34 ILLINOIS MS4 PERMIT
35 Under the Clean Water Act, states must issue National Pollution Discharge Elimination System (NPDES)
36 permits for stormwater discharges from industrial, construction and municipal activities. The permit for
37 small municipalities, those with fewer than 100,000 people, is known as the small municipal separate
38 storm sewer system or ―MS4‖ permit. IEPA first issued its Phase II MS4 permit in 2003, designated as
Click tabs to swap between content that is broken into logical sections.