00802530

Component

https://doi.org/10.3141/1720-12

http://scholar.google.com...lenn&publication_year=2000

In situ treatment design for pavement storm water runoff continues to pose unique challenges because of the unsteady nature of processes such as rainfall runoff, mobilization, partitioning, and delivery of heavy metals. Storm water from pavements and roadways transports dissolved, colloidal, and suspended solids in a heterogeneous mixture, and along with pH, alkalinity, traffic levels, and residence time, influences the partitioning of heavy metals. For effective in situ treatment design, an understanding of heavy metal partitioning and temporal wash-off during a rainfall runoff event is a prerequisite. This study investigates zinc (Zn), cadmium (Cd), copper (Cu), and lead (Pb) partitioning, cumulative loadings, and wash-off in storm water pavement sheet flow from a heavily traveled urban interstate pavement site. Results are presented for a series of eight rainfall runoff events at the instrumented site. Results from partitioning analysis (heavy metal mass transfer) between the dissolved and particulate-bound fractions indicate that Zn, Cd, and Cu masses are predominately dissolved in pavement sheet flow. Although a relatively insoluble heavy metal, Pb mass was also mostly dissolved. These high dissolved fractions can be attributed to low urban rainfall pH levels, relatively short pavement residence times for the pavement sheet flow, and low pavement runoff alkalinity. Plots of cumulative heavy metal mass as a function of elapsed runoff time clearly demonstrate that during all events the pavement sheet flow dissolved fractions dominated the particulate fractions for Zn, Cd, Cu, and Pb. As far as delivery, results also indicate that the dissolved masses for Zn, Cd, Cu, and Pb generally exhibited a "first flush" compared with their particulate masses. The design of in situ treatment systems or source control best management practices loaded by pavement sheet flow require data on partitioning and loading for effective treatment.

This paper appears in Transportation Research Record No. 1720, Roadside Safety Features and Hydraulic, Hydrology, and Water Quality Issues.

English

p. 100-111

2000

Transportation Research Record

0309066980

Figures (8) ; References (17)

Alkalinity; Cadmium; Copper; Heavy metals; Interstate highways; Lead (Metal); pH value; Rainfall; Runoff; Storms; Urban areas; Zinc

In situ treatment; Pavement sheet flow; Temporal variations

Highways; Hydraulics and Hydrology; I26: Water Run-off - Freeze-thaw

TRIS, TRB, ATRI

Nov 16 2000 12:00AM

• CALIFORNIA DEPARTMENT OF TRANSPORTATION STATEWIDE STORM WATER MANAGEMENT PROGRAM
• DESIGN AND DEVELOPMENT OF STEEL BREAKAWAY POSTS
• ESTIMATION OF TIME OF CONCENTRATION FOR MARYLAND STREAMS
• EVALUATING HUMAN RISK IN SIDE IMPACT COLLISIONS WITH ROADSIDE OBJECTS
• EVALUATION OF PORTABLE CONCRETE BARRIERS USING FINITE ELEMENT SIMULATION
• IMPACT PERFORMANCE OF THE G4(1W) AND G4(2W) GUARDRAIL SYSTEMS: COMPARISON UNDER NCHRP REPORT 350 TEST 3-11 CONDITIONS
• IN-SERVICE, PERFORMANCE-BASED ROADSIDE DESIGN POLICY: PRELIMINARY INSIGHTS FROM WASHINGTON STATE'S BRIDGE RAIL STUDY
• LONG-SPAN GUARDRAIL SYSTEM FOR CULVERT APPLICATIONS
• PERFORMANCE OF BREAKAWAY CABLE AND MODIFIED ECCENTRIC LOADER TERMINALS IN IOWA AND NORTH CAROLINA: IN-SERVICE EVALUATION
• SAFETY EFFECTIVENESS OF UPGRADING GUARDRAIL TERMINALS TO NCHRP REPORT 350 STANDARDS
• TEST LEVEL 4 BRIDGE RAILS
• TRANSITIONS FROM GUARDRAIL TO BRIDGE RAIL THAT MEET SAFETY PERFORMANCE REQUIREMENTS