Pollution Control Planning: NCAP, Inventories and Siting
Pollution Control Planning asks how monitoring, inventories and modelling become city, river or regional action plans. Expect non-attainment cities, NCAP targets, source apportionment, carrying capacity and EIA-linked planning.
Planning instruments
The National Clean Air Programme (NCAP), launched in 2019, initially covered 122 non-attainment cities and set a 20–30% reduction target for PM2.5 and PM10 by 2024 against a 2017 baseline. City action plans combine source apportionment, emission inventories, monitoring network design, traffic and dust control, industrial inspections and public communication. For Delhi-NCR, the Graded Response Action Plan (GRAP) links forecast air quality to escalating restrictions. For rivers, action plans use assimilative capacity, sewage gap analysis and industrial consent enforcement.
Technical core
An emission inventory multiplies activity data by emission factors. Dispersion models (AERMOD, CALPUFF) translate emissions into ambient concentrations. Carrying capacity is the load a region can accept without breaching standards. Siting rules keep polluting industries away from residential areas, water bodies and ecologically sensitive zones. Under EIA Notification 2006, Category A projects go to the central expert appraisal committee and Category B to state authorities; the process includes screening (B only), scoping, public consultation and appraisal.
Worked example
A city's PM2.5 is 100 µg/m³. Source apportionment gives traffic 40%, road dust 25%, industry 20% and biomass 15%. A traffic measure cuts traffic PM2.5 by half: reduction = 100 × 0.40 × 0.50 = 20 µg/m³, giving 80 µg/m³. That is still above the 24-h standard of 60 µg/m³, so the plan must add dust and industry controls.
Traps
NCAP targets PM, not all pollutants; the baseline year matters; a source apportionment percentage is of measured PM2.5, not of total emissions; non-attainment and critically polluted are different designations; EIA screening applies to Category B, not A.