Construction creates dust—demolition, excavation, concrete cutting, material transport. Dust concentrations on construction sites reach 200-500 µg/m³ in active areas, 5-10 times ambient air quality standards. Downwind residential areas experience elevated dust exposure. Regulatory authorities enforce dust limits through permitting: monitoring demonstrates compliance, alerts enable rapid response when limits approach, failure requires mitigation implementation.
Construction Dust Sources and Monitoring Strategy
Dust generation activities: Demolition (highest dust generation—concrete breaking, crushing, sorting). Excavation (moving earth, creating exposure). Concrete cutting (diamond blade creates fine dust). Material stockpiles (wind erosion from exposed material piles). Transport (vehicle movement on unpaved roads, spillage). General construction (dust from all activities combined). Typical site might generate 100+ tonnes dust monthly during active demolition, <10 tonnes during finishing phases.
Dust monitoring strategy: Real-time monitors at sensitive receptors (downwind residential areas) provide immediate alerts when dust approaches limits, enabling rapid mitigation (water spray, tarping). Compliance monitors (gravimetric samplers at boundary) collect legal evidence for regulatory reporting. Continuous monitoring combines both: real-time alert capability + gravimetric evidence.
Dust monitoring per IAQM guidance requires: PM10 measurement at sensitive receptors (residential areas), boundary measurement at site perimeter, background air quality measured at reference location (upwind), daily monitoring during active works. Reporting: daily results compared to limits, exceedance investigation and mitigation documentation.
Construction Air Quality Standards and Best Practices
Dust control measures per HSE construction standards: Engineering controls (dust barriers, wind fencing, enclosures) prevent dust generation. Operational controls (water spray, speed limits on unpaved roads, frequent sweeping) reduce dust propagation. Administrative controls (schedule high-dust activities during low-wind periods, avoid activities during sensitive times). Response procedures (monitoring alert triggers immediate investigation, mitigation if limits approach).
Water spray systems: Water suppresses dust mechanically. Spray systems deployed during demolition reduce airborne dust 60-80%. Challenges: water disposal (containing runoff), equipment maintenance (nozzle clogging, pressure maintenance), weather dependency (wind reduces spray effectiveness, rain reduces spray necessity). Cost: £5,000-20,000 installation, £500-2,000 monthly operation.
Dust barriers and enclosures: Physical barriers (fencing, netting) prevent dust dispersion. Effective for fixed dust sources (stockpiles, crushing operations). Mobile enclosures (temporary structures) control dust during specific activities. Effectiveness: 50-90% depending on design. Cost: £10,000-50,000 depending on perimeter and height.
Site management practices: Minimise exposed material (cover stockpiles, stabilise exposed earth), hard surface roads (prevent dust generation from vehicle movement), wheel washers at site exits (prevent dust transport via vehicle wheels), frequent street sweeping of accumulated dust. Combined effort: 70-80% dust reduction achievable.