1. Soil Sampling and Laboratory Analysis
To assess contamination, soil samples are collected from various depths and locations across the land parcel. This process involves:
- Identifying sampling points based on historical land use, proximity to industrial activity, or storage of hazardous materials
- Collecting samples at multiple depths (e.g., 0–15 cm, 15–30 cm)
- Sending the samples to an accredited environmental testing laboratory
The lab tests for pollutants such as:
- Heavy metals (lead, arsenic, mercury, cadmium)
- Petroleum hydrocarbons and industrial solvents
- Pesticide residues and chemical contaminants
- pH, electrical conductivity, and organic matter content
This data helps determine the suitability of the soil for development, agriculture, or industrial reuse.
2. Groundwater Quality Assessment
In many cases, groundwater samples are also collected from borewells or test pits on the property to check for:
- Contamination from leachates, effluents, or heavy metals
- Oil or chemical seepage from above-ground or underground storage
- Compliance with BIS and CPCB drinking water standards, especially in regions with high water table
Abnormal groundwater parameters can indicate subsurface pollution, which could affect land value and future usability.
3. Review of Historical Land Use and Industrial Activity
A critical component of pollution testing is understanding the past use of the land, including:
- Operation of factories, workshops, chemical storage units, or dump yards
- Proximity to polluting industries or waste treatment plants
- Examination of government records, environmental clearance documents, or local reports
This helps in determining if the land is at risk of legacy contamination and whether site-specific investigations are needed.
4. Surface and Subsurface Contaminant Screening
Specialized tests may be conducted using:
- Geophysical surveys to detect buried waste, tanks, or anomalies
- X-ray fluorescence (XRF) for rapid in-field heavy metal screening
- Gas chromatography to identify volatile organic compounds (VOCs) in soil or vapors
These techniques provide a more detailed understanding of hidden contaminants that may not be visible on the surface.
5. Environmental Site Assessment (ESA)
For large land deals or industrial properties, a formal Environmental Site Assessment (ESA) is often carried out in two stages:
- Phase I ESA: Desk-based review of records, site visits, interviews, and visual inspection
- Phase II ESA: Intrusive testing such as drilling, sampling, and laboratory analysis based on Phase I findings
This is widely used by buyers, banks, and regulatory authorities to assess environmental risks and compliance.
6. Monitoring Against CPCB and SPCB Guidelines
Testing is performed in alignment with standards and permissible limits set by:
- The Central Pollution Control Board (CPCB)
- The respective State Pollution Control Board (SPCB)
- ISO standards for environmental management and land quality assessment
This ensures that results are legally acceptable and can be used for compliance declarations or clearance applications.
7. Certification and Reporting
The outcome of the testing is compiled in an Environmental Testing Report, which includes:
- Summary of test results vs. permissible limits
- Recommendations for remediation, if required
- Statement of land suitability for sale or development
This report is often reviewed during legal due diligence, financing, or regulatory clearance processes.
