Bill Selbig USGS – WRD Middleton, WI

1. Evaluation of Street Sweeping as a Water Quality Management Tool in Three Residential Basins in Madison, WI Bill Selbig USGS – WRD Middleton, WI

8. Can it Make a Difference?

9. Objectives • Primary • Determine if the dirt load on residential streets is reduced by street sweeping and if so, to what extent • Determine if reduction in street dirt load results in detectable change in water quality • Secondary • Evaluate benefits of different street sweepers • Evaluate benefits of various sweeping programs (frequency) • Characterize distribution of sediment particle size on street surfaces

10. Paired Basin Approach Response of Total Solids Concentration to Basin Change Test - Pre Test - Post Control

11. BASIN NEEDS • 4 basins total (3 test basins and 1 control basin ) • 3 basins equipped to monitor and sample stormwater • 1 basin having only street dirt characterization SELECTION CRITERIA • Proximity • Age • Topography • Street condition • Drain to a single point • Logistics (power available?) Selection of Basins

13. Land Use Within Control and Test Basins

15. Proposed Street Sweeping Schedule 2001 - 2004 * * Introduction of Whirlwind sweeper and plastic bristles to study

16. Two – Pronged Approach to Evaluate Street Sweeping Effectiveness • Characterize street dirt loading on weekly basis • Accumulation rates • Seasonal fluctuations • Distribution over street (curb vs. centerline) • Particle-size distribution • 2. Characterize pollutant loading during storm events • Wash-off functions • Seasonal fluctuations • Particle-size distribution • Bedload transport

19. Reducing Variability in Street Dirt Data • Vacuuming 3 streets per basin • Vacuum from curb to curb with 6” nozzle • Vacuum strips are random but approximately 100 ft. apart • Streets are measured individually then summed into a single basin 4.25 (s-1)2 N = --------------- where, ā = mean (rā)2 s = standard deviation r = allowable error N = number of subsamples required (Hansen et al 1984):

20. Reducing Variability in Street Dirt Data (cont.)

22. Street Lengths in Study Area Street Feet Curb-miles

23. Breakdown of particle sizes • Detritus • >2000um • 1000 – 2000um • 500 – 1000um • 250 – 500um • 125 – 250um • 63 – 125um • <63um

24. Distribution of Particle Size

25. Total Basin Street Dirt Load, in lbs./curb mi, for No Sweeping and Sweeping Years May precip. 4.67” 11.86” No Sweeping No Sweeping No Sweeping Sweeping No Sweeping Sweeping No Sweeping Sweeping

26. PELICAN CONTROL CITY Comparison of total basin street dirt load, in lbs./curb mile, during non-sweeping phase CROSSWIND June 2001 – September 2002 * May – Sept. 2002 *

28. PELICAN CONTROL CITY CROSSWIND Comparison of total basin street dirt load, in lbs./curb mile, during sweeping phase April 2003 – September 2004

34. PELICAN ROBUST REGRESSION POST SWEEPING (lbs./curb mi.) PRE SWEEPING (lbs./curb mi.)

35. CROSSWIND ROBUST REGRESSION POST SWEEPING (lbs./curb mi.) PRE SWEEPING (lbs./curb mi.)

36. WHIRLWIND ROBUST REGRESSION POST SWEEPING (lbs./curb mi.) PRE SWEEPING (lbs./curb mi.)

37. Minimum initial load for which sweeping has a positive effect Summary of Sweeper Efficiency

38. Why do different technologies perform similarly? Majority of street dirt lies within 3 feet of the curb

41. Broom technology cannot efficiently remove particles trapped in pockets or uneven surfaces Pre Sweeping Post Sweeping

44. WATER QUALITY

45. Constituent List Analyses performed by City of Madison Dept. of Public Health • Ammonia – Nitrogen • NO2 + NO3 • Kjeldahl Nitrogen • Total Phosphorus • Suspended Solids • Total Dissolved Solids • Chloride • Hardness • Calcium • Magnesium • Total Cadmium • Dissolved Cadmium • Total Copper • Dissolved Copper • Total Lead • Dissolved Lead • Total Zinc • Dissolved Zinc • Suspended Sediment • Particle Size Dist.