Abstract:
Infiltration experiments were undertaken to investigate an infiltration medium that could be used in retention basins to decrease the infiltration rate to between 5 and 10 inches per hour and to also decrease the concentrations of some pollutants in highway runoff. Fourteen infiltration media formulations were tested in small-scale preliminary infiltration tests to estimate their infiltration rates and select candidates for further study. Subsequent cylinder infiltrometer tests were then conducted using two of the media to gather additional infiltration rates estimates and to investigate the potential effects of the infiltration media on the water quality of highway runoff. A formulation of 70-percent sand, 15-percent clay, and 15-percent mulch had a steady-state infiltration rate of between 1 and 3 inches per hour. Two bataches of the 90-percent sand, 5-percent clay, and 5-percent mulch formulation were tested. The first batch of the formulation had a steady-state infiltration rate of betwen 9 and 10 inches per hour and was consistent between replicate tests. The second batch had a steady-state infiltration rate of approximately 36 inches per hour, and a subsequent test using the second batch in a second infiltrometer had a steady-state infiltration rate of approximately 50 inches per hour.Water-quality samples taken prior to and after infiltration of highway runoff through the 90-percent sand, 5-percent clay, and 5-percent mulch formation indicate that there may be a decrease in the concentrations of dissolved copper, lead, zinc, and cadmium as well as total petroleum hydrocarbons and nitrate plus nitrite. The infiltration medium may also increase the concentrations of total and dissolved arsenic, total lead, total copper, and suspended and dissolved solids. Further testing would be needed to establish if the changes in water quality are statistically significant.

Authors:
Ames,K. C., Inkpen,E. L., Frans,L. M., Bidlake,W. R.

Keywords:
runoff, infiltration, retention basins

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External Links: http://wsdot.wa.gov/Research/Reports/500/512.2.htm

Abstract:
This project examined the role that road shoulders play in the stormwater runoff process. The goal of the research was to determine the type of shoulder treatment that yields the least quantity of runoff of the highest quality. Three types of shoulder materials were tested: conventional asphalt, gravel, and porous asphalt. Porous asphalt allows water to penetrate and flow through the pavement to a sublayer, and it can be used in place of conventional asphalt on low-traffic roadways. Each of the three shoulder materials were tested in duplicate on a heavily traveled, two-lane road north of Redmond, Washington. Stormwater runoff from the road flowed onto the shoulder test sections and was collected in a stormwater collection system at the base of the test sections. Flow-weighted composite samples were collected, and both runoff quantity and quality were evaluated.On the basis of results from 11 storms monitored between November 1995 and August 1996, several trends were identified. the porous asphalt shoulders demonstrated a greater potential to reduce runoff volumes and peak discharge rates than gravel and conventional asphalt shoulders. During typical wet season storms (.76 cm [.3 in]), the porous asphalt and gravel shoulder test sections reduced runoff volumes by approximately 85 and 30 percent, respectively, in comparison to the conventional asphalt test sections. The ability of the porous asphalt and gravel shoulder test sections. The ability of the porous asphalt shoulders to reduce pollutant loads far exceeded that of the gravel and conventional asphalt shoulders. During typical wet season storms the solids and pollutant loads from the porous asphalt shoulders were more than 90 percent lower than the loads from the conventional asphalt shoulders. The gravel shoulders yielded load reductions ranging from 10 to 70 percent lower than the conventional asphalt, although orthophosphorus load exceeded those of the conventional asphalt shoulder by nearly 30 percent.Removal rates were highest for those pollutants that were correlated with total suspended solids (0.70
Authors:
St.John,M. S., Horner,R. R.

Keywords:
road shoulder, porous asphalt, runoff, pollutant loading, research

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Abstract:
This report present the final form of the Washington State Highway runoff pollutant loading model, incorporating data from the five years of study. It also features a probabilistic analysis of concentration and loading data designed to express the chance of exceeding specific values in a given case. Other topics include further assessment of the toxicity of highway runoff and its causes and mitigation.

Authors:
Little,M. L., Horner,R. R., Mar,B. W.

Keywords:
analysis, Assessment, data, highway, highway runoff, ITS, mitigation, model, pollutant loading, runoff, stormwater, Toxicity, Washington, Washington state

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Abstract:
Statewide sampling of highway runoff continued through 1980-81, and the resulting data has been aggregated with that from previous years to further investigate pollutant loadings. Results have validated the solids loading model previously proposed by Asplund (1980) for Western Washington Highways and tentatively extended the model to Eastern Washington. Loading of there pollutants can be predicted from total suspended solids loading using ratios derived from the data. These ratios may be taken as constants at any Washington State location for some pollutants or as linear functions of traffic or other contaminants. Comparison of runoff from a sulfur-extended asphalt pavement with runoff elsewhere indicates higher sulfate loads in the former case. A limited sampling program along an uncurbed highway section observed higher pollutant concentrations from these sections to curbed areas. Sampling of solids adhering to the undercarriage of automobiles produced widely varying results but suggested that vehicles traveling on rural or unpaved roads accumulate significant amounts of solids that can be released on highways. The final year of field sampling will concentrate on improving the loading models, especially for Eastern Washington application, and continuing the sulfur extended asphalt study with a functional control site experiencing the same conditions.

Authors:
Tai Wik,David Chui, Mar,B. W., Horner,R. R.

Keywords:
analysis, asphalt, asphalt pavement, Concentrations, condition, control, data, extended asphalt, highway, highway runoff, Highways, loads, model, models, pavement, pollutant loading, Pollutants, program, runoff, rural, sampling, statistical analysis, sulfur, suspended solids, traffic, Washington, Washington state

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Abstract:
The impacts of storm water runoff from Washington State freeways on aquatic ecosystems were investigated through a series of bioassays utilizing algae, zooplankton and fish.Algae and zooplankton were adversely affected by the soluble fraction of the runoff, while suspended solids caused high mortalities of rainbowtrout fry . In addition,. BOD 5 values similar to those reported in the storm water literature were measured; however, there were indications that results were influenced by toxicity to microbial populations.

Authors:
Portele,G., Mar,B. W., Horner,R. R., Welch,Eugene

Keywords:
Algae, Biochemical Oxygen, Biomass, control, Demand, fish, freeway, heavy metals, highway, highway runoff, impact, impacts, Interim, metals, population, runoff, stormwater, suspended solids, Toxicity, transport, Washington, Washington state, Water Pollutants, Washington State Monitoring, zooplankton

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Abstract:
A highway storm water runoff pollutant loading. model has been developed based on results from con3posire sampling of approximately 600 storms at nine locations in the State of Washington over five years. The model expresses total suspended solids (TSS) loading in proportion to the product of highway segment length, average runoff coefficient, and vehicles traveling during storm periods. It was dem-onstrated that loadings of contaminants such as chemical oxygen demand, nutrients and trace metals could be estimated from TSS loadings using ratios derived from the data, The model described was developed and validated for assessing total loadings over a time span encompassing a number of storms (monthly or annually). To predict pollutant concentrations and loadings in runoff from a given storm, cumulative distributions were plotted and analyzed to determine the probability of exceeding specific concentration and loading values in a given case. Bioassay studies using highway runoff indicated toxicity to aquatic life when elevated metals deposition from high traffic volumes (in excess of 10,000 -20,000 vehicles per day) or high metals concentrations in rainfall caused runoff concentrations to exceed lethal levels. Draining highway runoff through grass channels 60 meters in length greatly reduced TSS and metals concentrations and the consequent toxic effects. The major product of this research is a guide to assessing and mitigating the impacts of highway runoff to receiving waters.

Authors:
Mar,B. W., Horner,R. R., Spyridakis,D. E., Welch,E. B.

Keywords:
Assessment, Channel, Chemical, Concentrations, data, demand, deposition, developed, highway, highway runoff, impact, impacts, Loadings, Highway runoff, metals, mitigation, model, models, pollutant loading, Pollutants, quality, rainfall, research, runoff, sampling, span, stormwater, suspended solids, Toxicity, traffic, traffic volumes, volume, Washington, Washington state, water quality

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Abstract:
This report summarizes findings detailed in Report Nos. 4 and 5 plus the work of Zawlocki on trace organics in highway runoff. Several hundred compounds tentatively, identified by GC-MS were grouped into nine categories, which were not mutually exclusive. Major components of-these 'categories were petroleum products used by vehicles and incompletely combusted hydrocarbons. The concentrations of these trace organics groups were low compared to criteria proposed for protection of aquatic life.

Authors:
Mar,B. W., Ferguson,J. F., Welch,E. B.

Keywords:
Concentrations, construction, criteria, group, highway, highway runoff, Highways, hydrocarbons, Leachate, Organics, petroleum, protection, quality, runoff, Water Pollutants, Washington State Monitoring, water quality, Woodwaste fills

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Abstract:
This report focuses on the results of four research thrusts that resulted in dissertations and condensed research reports during this reporting period. There are now 14 project reports either completed or close to completion, as shown in Table 1; this report summarizes the results reported in numbers 10-12. Also summarized in Table 1 are the reports planned for the remainder of the project.

Authors:
Mar,B. W., Ferguson,J. F., Spyridakis,D. E., Welch,E., Horner,R. R.

Keywords:
project, quality, research, runoff, water quality

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Abstract:
Trace organics were surveyed using gas chrornotography coupled to mass spectrometry for highway runoff samples from two Seattle sites . The characterization of the organics exhibited concentrations of aliphatic, aromatic and complex oxygenated compounds. Vehicles, including.exhaust emissions, were concluded to be the source of many of the organics.

Authors:
Zawlocki,K. R., Ferguson,J. F., Mar,B. W.

Keywords:
Concentrations, emissions, highway, highway runoff, Interim, Organics, runoff, seattle, survey, Washington, Water Pollutants, Washington State Monitoring

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Abstract:
Mass balances conducted on soils adjacent to highways indicated low mobility of metals deposited on well-vegetated surfaces. Grass drainage channels were shown to effectively capture and retain metals (e.g. a 60 m channel removed 80 percent of the original Pb concentration). Mud or paved channels, however, demonstrated little or no ability to remove metals from runoff. Metal release studies suggested that acid precipitation could release metals bound in the soil, especially where low buffering capacity exists.

Authors:
Wang,T. S., Spyridakis,D. E., Mar,B. W., Horner,R. R.

Keywords:
capture, deposition, drainage, embankment, Embankments, heavy metals, highway, Highways, impact, impacts, metals, mobility, overland flow, quality, runoff, soil, transport, Washington state, Water pollutants, water quality

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Abstract:
An extensive literature review , laboratory column study and field observations indicated that leaching of soluble pollutants from woodwaste submerged in groundwater will be completed within a few years. Longer periods of leaching will be generated by woodfills above groundwater exposed to precipitation or infiltration of runoff. Expressions to model the quantity and characteristics quality of leachate from woodwaste fills used for road embankments were developed, and mitigating measures to reduce the impact of leachates are proposed.

Authors:
Vause,Kurt H., Ferguson,John F., Mar,B. W.

Keywords:
column studies, developed, embankment, Embankments, highway, impact, impacts, infiltration, Leachate, model, Pollutants, quality, review, runoff, water quality, Woodwaste fills

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Abstract:
A composite sampling device was developed that can be installed at less than ten percent of the cost of automatic sampling systems currently used in Federal highway runoff studics. This dcvi ce was operated for one year, along-side an automatic sampler at the 1-5 side, to demonstrate that the two systems provide statistically identical storm composites.

Authors:
Clark,David L., Mar,B. W.

Keywords:
cost, developed, highway, highway runoff, Interim, runoff, sampling, System, systems, Water Pollutants, Washington State Monitoring

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Abstract:
A total of 241 storm events were sampled at ten sites during the first full year of statewide monitoring of highway runoff. Analyses of these data indicates that more than half of the observed solids in this runoff is traced to sanding operations. The total solids loading at each side-was correlated with traffic during the storm. The ratio of other pollutants to solids was linear when there was sufficient traffic-generated pollutants to saturate the available solids.

Authors:
Asplund,Randy L., Ferguson,John F., Mar,B. W.

Keywords:
data, highway, highway runoff, models, monitoring, Pollutants, runoff, traffic, Washington, Washington state, Water Pollutants, Washington State Monitoring

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Abstract:
This report covers the initial 15 months of effort to review the literature, select a prototype site, compare the performance of several automatic sampling devices, and install a prototype sampling site on 1-5 north of Seattle .

Authors:
Horner,R. R., Burges,S. J., Ferguson,J. F., Mar,B. W., Welch,E. B.

Keywords:
highway, highway runoff, Interim, monitoring, performance, review, runoff, sampling, seattle, Water Pollutants, Washington State Monitoring

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Abstract:
Criteria for selecting statewide monitoring sites for highway runoff were established t o provide representative combinations of climate, traffic highway, land use, geographic and topographic characteristics , Using thesecriteria , a minimum of six sites - were recommended for use to this research.

Authors:
Aye,Robert C.

Keywords:
criteria, highway, highway runoff, land use, land-use, monitoring, research, runoff, traffic, Water Pollutants, Washington State Monitoring

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Abstract:
A study was conducted on the character and significance of highway runoff waters for the Washington Department of Highways and the Federal Highway Administration. This preliminary appraisal of runoff quality consisted of a literature review and critique plus a limited amount of field sampling on SR 520. Although a large amount of information is present in the literature concerning urban run off, there is very little strictly related to highways and their rights-of- way. Highway runoff is similar t o urban area runoff but may be higher in heavy metals and oil. A significant fraction of the heavy m e t an l s, oil and nutrients are adsorbed to the dust and dirt fractions and then may be removed by sedimentation. Runoff from the lake bridges should have a very insignificant effect on Lake Washington in comparison with the urban run off to the Lake. Recommendations are made for mitigating runoff effects and for conducting an intensive study of highway run off water quality and its significance.

Authors:
Sylvester,Robert O., DeWalle,Foppe B.

Keywords:
bridge, bridges, environment, heavy metals, highway, highway runoff, Highways, ITS, metals, quality, review, runoff, sampling, sedimentation, Study, urban, vehicle emissions, Washington, water quality

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