Environmental Indicators and Road Salt Impact

Environmental Indicators

• Tools evaluate environmental state and signal changes important to society
• Comprehensive indicators needed to reflect societal concerns, information needs, and management strategies
• Assess current ecosystem conditions and document trends over time
• Anticipate degradation early and identify cause of degradation
• Demonstrate links between system components

Factors Affecting the Dispersion of Road Salt

• Road type (e.g., highways, residential streets) requires varying salt application amounts due to differing traffic volume and speed
• Salt dispersion patterns influenced by these differences
• Snow clearing practices (frequency, methods, and efficiency) determine how much salt remains on the road versus removal
• Drainage infrastructure design affects how and where road salt is carried, potentially reaching water bodies or infiltrating soil
• Subsurface geology (soil type and conditions) influences salt infiltration into the ground and potential groundwater impact
• Lawn irrigation near roads can dissolve salt residues and accelerate chloride ion transport into soil and nearby water systems
• Seasonal conditions (temperature, precipitation, snowmelt) significantly impact salt application rates and salt movement
• Road salt losses impact freshwater and terrestrial ecosystems, and drinking water supplies
• 10-20 million tons of road salt annually applied in the USA over the last 50 years
• Urban settings have very low attenuation potential for road salt (NaCl) around municipal wells
• Non-point source with highly variable surface loading

Landscape-Based Approach to Stormwater Management

• Watersheds are the natural and logical boundary for environmental and land use planning
• Types of environmental studies required for development must be considered, along with expertise levels needed
• Evidence shows that urban design and stormwater management approaches are unsustainable over the long term, if watershed goals need to be realized
• Need for enhancements to stormwater management within existing urban areas
• Need for diverse technologies and disciplines for effective, successful large-scale stormwater management
• Low-impact development (LID), principles, and green building certifications represent advanced stormwater management

Low-Impact Development (LID)

• Sustainable approach to managing stormwater, mimicking natural hydrological processes
• Reduces runoff volume, improves water quality, and enhances groundwater recharge by promoting infiltration, evaporation, and transpiration
• LID techniques include green infrastructure, permeable pavements, rainwater harvesting, and vegetated buffer strips

Treatment Train Approach

• Series of practices and approaches meeting stormwater management objectives in an area (Source, Conveyance, and End of Pipe controls)
• Source control: reduce runoff, pollutant loading (green roofs, permeable pavements, rainwater harvesting)
• Conveyance control: managing stormwater flow (bioswales, infiltration trenches, check dams)
• End-of-Pipe controls: treat or manage stormwater before discharge (retention ponds, wetlands, oil-grit separators)

Water Quantity and Quality Control Mechanisms

• Strategies to address stormwater volume and pollution in urban areas
• Water quality control mechanisms reduce pollutant loads (screening, filtration, infiltration, biological uptake)
• Water quantity control manages stormwater runoff reduce flooding and erosion (detention basins, retention ponds)

Rainwater Harvesting

• Capture, diversion, and storage of rainwater for use in irrigation, drinking water, and domestic purposes (collecting, storing, distributing)

Stormwater Retrofit

• Stormwater treatment on existing development, potentially untreated or inadequately treated by BMPs
• Aiming to reduce pollutants and restore habitat
• Fixing issues, maintenance, reducing runoff volumes, reducing pollutants of concern, and supporting stream restoration

Water Quality Control Mechanisms

• Rate reduction techniques to mimic pre-development or natural conditions
• Volume reduction techniques (storage, infiltration, velocity control)

Design Characteristics of Grassed Swales

• Shallow, vegetated channels for conveying, treating, and infiltrating stormwater runoff
• Provide natural, sustainable alternative to conventional stormwater systems like curbs and gutters

Levels of Protection

• Enhance protection: Sensitive aquatic habitats (low pre-development erosion characteristics, habitat sensitive to siltation), removal of 80% suspended solids.
• Normal protection: Less sensitive aquatic habitats, removal of 70% suspended solids.
• Basic protection: Areas where downstream aquatic habitat has adapted to high suspended solids loads, removal of 60% suspended solids.

Stormwater Management Ponds

• Detention ponds: Store runoff, release slowly to reduce peak flows
• Retention ponds: Permanently hold water, allow sediments/pollutants to settle

Green Roofs

• Roof surface partially or fully filled with vegetation, installed over a waterproof membrane
• Provide multiple environmental and energy benefits
• Reduce runoff, regulate temperature, improve air quality

First Flush Phenomenon

• Initial portion of runoff in a rainfall event, contains disproportionately high pollutant concentration.

This quiz explores key concepts about environmental indicators and their role in assessing ecosystem conditions. It also examines factors influencing road salt dispersion and its environmental effects, including road type, snow clearing practices, and drainage design. Test your knowledge on how these elements interact and impact our ecosystems.