Environmental Impact, Pollution, Waste Management and Sustainable Development
Domain 9 tests impact assessment, pollutant behaviour and waste hierarchy, applied to a densely populated, tourism-driven archipelago with limited land, scarce water and fragile coasts. Expect to evaluate an activity (a road, a desalination plant, a wind farm, a landfill) and argue a defensible position using indicators.
Impact assessment
Environmental impact = alteration of the environment caused by an action. The procedure: screening, scoping, baseline study, identification and prediction of impacts, mitigation, environmental impact statement, public participation and monitoring. Spanish law distinguishes ordinary, simplified and strategic environmental assessment. Impacts are classified by sign, magnitude, persistence, reversibility, synergy and cumulative effect - the last matters because many small island impacts add up.
Pollution by medium
Air: SO₂, NOₓ, CO, O₃, particulates PM10/PM2.5, heavy metals; acid rain; photochemical smog; in the Canaries, Saharan dust (calima) adds natural particulate load. Water: organic load and eutrophication (nitrates, phosphates), heavy metals, hydrocarbons, thermal pollution, desalination brine and its effects on seagrass. Soil: salinisation, heavy metals, pesticides. Noise and light pollution disrupt seabird fledglings (petrels and shearwaters) - a specific, examinable Canarian issue.
Waste management
Hierarchy: prevention > reuse > recycling > recovery (energy) > disposal. Fractions: organic (compost/biogas), packaging, glass, paper, WEEE, hazardous. Island constraints: no large landfill space, export costs, high seasonal waste peaks from tourism.
Sustainability
Sustainable development meets present needs without compromising future generations (Brundtland). Indicators: ecological footprint, biocapacity, water footprint, resilience. Island carrying capacity is limited by water, land and waste absorption. Tools: renewable energy, energy efficiency, circular economy, tourism carrying-capacity limits, environmental taxes, SDGs.
Worked example
Evaluate a planned desalination plant for a tourist area. Reasoning: positives - reliable water independent of rainfall, low land footprint, quality control. Negatives - high energy demand (CO₂ unless renewables), brine discharge raising salinity and harming seagrass meadows, high cost. Mitigation - renewable power purchase, brine diffuser design and monitoring, blending with groundwater. Verdict - acceptable only with siting away from sensitive seagrass and energy from renewables; otherwise cumulative coastal impacts outweigh the gain.
Traps that cost marks
Calling any impact 'irreversible' without justification. Confusing mitigation with compensation. Ignoring cumulative and synergistic effects. Forgetting that noise and light are pollutants.
- Waste hierarchy order is examined as a sequence.
- Brine is the key impact of desalination, not the water itself.
- Calima contributes natural PM10, so source apportionment matters.
- Light pollution is a specific Canarian biodiversity issue.
- Carrying capacity is set by the scarcest resource: usually water on islands.