- NATIONAL HIGHWAY RUNOFF WATER-QUALITY DATA
- AND METHODOLOGY SYNTHESIS
EXECUTIVE SUMMARY
A series of environmental laws, executive orders, and policies addressing the potential threat of highway runoff to the Nation's water resources heightens the Federal and State transportation agencies' environmental responsibilities for policies and programs. The Federal Highway Administration (FHWA), the U.S. Geological Survey (USGS), the U.S. Environmental Protection Agency (EPA), and many State highway departments and universities have sponsored or conducted research on the nature and impacts of highway runoff on water quality. However, a composite of these data is not available in a central location, and the existing data may present conflicting information. A synthesis of national highway runoff water-quality data and methodology is required, which would involve assembling, evaluating, and cataloging the existing information. Existing data, and studies from the FHWA, the USGS, State DOT's, and other sources will be compiled and evaluated to determine whether the information needs of highway managers, practitioners, and researchers are met, and whether this information will meet future needs. The USGS will examine technical issues with input from the FHWA, and once consensus is reached, produce a report that details the adequacy of the existing data, and the existing concepts to characterize and define the water quality of highway runoff. Where data are insufficient, monitoring plans will be developed to address recognized deficiencies.
Continuing FHWA and USGS research identifies and quantifies various pollution sources, resulting in improved runoff management practices to lessen effects of highway runoff on the water quality of receiving waters. Highway management practices have improved with the increased understanding gained from this research; however, over time, more accurate sampling techniques have evolved and some highway characteristics have changed. These changes have generated a need to compile and review previous impact study information, develop a new understanding of the processes involved, and identify information gaps. A review and synthesis of existing work will help assess how highway environmental changes such as new or changed highway construction techniques and materials, pesticides used in highway right-of-way maintenance, motor fuel constituents, engine emissions, and vehicle components effect the water quality of highway runoff. A comprehensive evaluation of available process-oriented research also would identify additional research areas necessary for continued reduction of unwanted water-quality constituents in highway runoff.
Background
In the early 1970's, a growing awareness of the potential for water-quality degradation due to highway runoff resulted in the enactment of environmental laws, executive orders, and policies that protect water quality. The acts and their requirements in relation to highway runoff include the following:
1. The National Environmental Policy Act and the Clean Water Act of 1972, as amended. These acts hold Federal decision makers accountable for activities having the potential to impact features of the natural environment-in particular, water quality (Bank, 1993).
2. The National Pollutant Discharge Elimination System (NPDES). This program requires discharge permits for industrial and municipal (point source) effluents containing pollutants. Effluent regulations include characterization of stormwater runoff, possibly originating directly from highways and the construction and maintenance of the highway systems.
3. The Nonpoint Source (NPS) Management Programs, Title 3, Section 319. This program also promotes the implementation of best management practices regarding highway runoff, as a potential nonpoint source pollutant of surface and ground water.
4. The Department of Transportation (DOT) National Transportation Policy (NTP), the Federal Highway Administration (FHWA) Environmental Policy Statement (EPS), and the Intermodal Surface Transportation Efficiency Act (ISTEA). These policies and acts specify increased environmental responsibilities for policies and programs developed by Federal and State transportation agencies.
5. The Coastal Zone Reauthorization Amendment (CZRA). This amendment regulates highway-runoff water quality and its environmental impacts in coastal areas.
6. Other legislation such as The Safe Drinking Water Act, the Endangered Species Act, the Resource Conservation and Recovery Act, and The National Wild and Senic Rivers Act also contain provisions that may pertain tho the water quality of highway runoff.
GOAL:
The primary goal of this proposed effort is to determine if the quality of and processes contributing to water-quality constituents in highway runoff can be adequately characterized nationwide, based on published information. The FHWA wants to check the validity of the existing data and procedures to assess and predict pollutant loadings and impacts from highway stormwater runoff. This study will be a first step that will either indicate that FHWA's current guidelines for highway runoff quality are up-to-date and technically supportable, or that additional information is needed to update the guidelines in subsequent steps. If there are gaps in areal coverage, changes in source chemistry, or lack of understanding, a monitoring or research plan to address these areas of deficiency will be proposed.
APPROACH:
To determine what information is available, and to assess the suitability of available data to validate runoff quality models developed by the FHWA a catalog of available data and investigations will be developed. The FHWA wants a catalog of existing studies and available data as well as an indication as to how robust the data are, and whether the data are sufficient to characterize pollutant loadings and impacts from highway and urban stormwater runoff, as well as the quality of atmospheric deposition since the mid-1980's around the country.