Highway Stormwater Runoff Quality: Investigation of Improved Operational, Predictive and Treatment Approaches for Winter Maintenance

February 13, 2019

12:00 – 1:00 pm
Instructor: Bill Trenouth

Course Description

Highway stormwater runoff from large, multi-lane highways is one of the leading causes of watercourse impairment worldwide. Road runoff frequently carries within it a substantial physicochemical pollutant burden, which includes sediments, nutrients, petroleum hydrocarbons and heavy metals. In seasonally cold climates, winter maintenance activities entail the use of road salts, which constitute an additional source of pollutant loading to the road surface. This webinar will focus on a multi-pronged approach that has been used to improve the state of practice surrounding highway design, management and the methodological application of treatment approaches.

First, a simple road salt application optimization tool was developed in order to help highway maintenance managers utilize a sound, scientifically defensible methodology when making determinations related to the frequency, timing and rate of road salt application. Data from three sites was used to modify the temperature index (TI) model to include sinusoidal variance in the daily melt coefficient, in addition to considerations related to the surficial rerouting of snow as well as the melt point depression caused by salt’s interaction with snow and ice. The second avenue of investigation led to the development of artificial neural networks (ANNs) capable of predicting the runoff concentration statistical distribution parameters for common heavy metals (Cu, Zn, Cr, Pb) and total suspended solid (TSS) event mean concentrations (EMCs) within highway stormwater runoff. The third avenue of investigation focused on the assessment and testing of novel treatment media for the purpose of enhancing existing roadside ditches in environmentally sensitive areas (ESAs). Blast furnace (BF) slag, basic oxygenated furnace (BOF) slag, iron-enriched overburden (IRON) and wood chips (WC) were tested. The long-term removal of Cr, Co, Cu, Pb, Ni and Zn within repacked soil columns ranged from 46-98%. The fourth research effort focused on the development of a methodological framework for designing enhanced roadside ditch systems for application in ESAs. The feasibility of this framework is demonstrated through a field-scale pilot study, complemented by three years of real-time monitoring data. Three different types of impermeable liner – compacted clay (CC), high density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) – were tested for their ability to prevent stormwater egress from the facility.

Learning Objectives:

1. Understand the impacts of stormwater runoff from multi-lane highways on watercourses
2. Learn about different design, management and methodologies to improve operational predicative and treatment approaches for highway winter maintenance.
3. Review and understand results of an in-field pilot study and real-time monitoring data.


Additional information:

IECA members are eligible to receive a 10% discount on registration.  To register at this discounted price please contact Victoria Kring at Victoria.Kring@trca.on.ca and provide your IECA member ID for membership confirmation.

Are you viewing this webinar with a group? You can add additional viewing attendees to your order, provided you are all viewing in the same location. Additional attendees qualify for a reduced registration fee of only $25!

If you have any additional questions, please contact Victoria Kring at Victoria.Kring@trca.on.ca
TRCA HST Registration number is 10808 8584 RT001