The document discusses changing stormwater regulations in Connecticut. Municipalities are increasingly requiring low impact development (LID) techniques to reduce stormwater pollution from development. LID aims to reduce impervious surfaces and runoff volumes to lower pollutant loads through techniques like bioretention basins, narrower roads, and permeable pavement. The document provides examples of LID projects and maintenance best practices to meet water quality goals and comply with new regulations.

1. Changing Requirements for Stormwater in Connecticut Connecticut Bar Association, Planning & Zoning Section New Haven, CT April 27, 2009 Presented by: Terrance Gallagher, P.E.

5. Conventional Catch Basin with Sump – limited sediment removal capacity, but no nutrient removal capability

7. Vortechnics Oil-Grit Separator – removes TSS, oil, grease & floatable debris – good “End of Pipe” treatment, but does nothing for controlling runoff volume or soluble nutrients

8. Perforated HDPE Pipe Bed – provides groundwater recharge under commercial parking lot

9. “ Wet” Detention Basin with multiple cells for increased filtering

11. Typical LID BMP – no curb & grass swales provide filtering parking lot runoff instead of catch basins and pipes

13. Minimizing Pavement – narrow roads in cluster subdivisions create less pollution

14. Biofilter Basin catches Road Sand before entering wetlands – allows for Town maintenance with backhoe

15. View Upstream at Biofilter Outlet – low tech solution that fits into New England landscape

16. Close-up of Tree Protection Measures during construction

17. Bioretention Basins incorporated into parking garage landscaping

18. Detail of Bioretention Basins – normally dry

19. Retrofitting bioretention into Existing Commercial Sites

20. Rain garden in an Endcap Island

22. Conventional Bituminous Asphalt and Porous Paver Blocks – Jordan Cove Subdivision –Waterford, CT

23. Detail of Eco-Stone Paver Blocks – set on crushed stone base to recharge runoff directly

24. Turfstone Pavers – control run-on from paved parking lot & provide parking for peak use

25. Infiltration Trench recharges sheet flow from parking lot prior to discharge to biofilter basin

26. Bioretention Basin provides filtering and volume control prior to discharging to wetlands

27. Bioretention Basins built successfully very close to inland wetlands without impacting wetlands.

28. “ Wet” Bioretention Basin with wetland seed mix treat runoff at the edge of the parking lot