Overview Hydrogeological Survey Report

Groundwater behaviour in the Indian subcontinent is highly complicated due to diverse geological formations with significant lithological and chronological variations, a complex tectonic framework, climatological differences, and various hydrochemical conditions. Several studies have revealed that aquifer groups in alluvial/soft rocks extend beyond the surface basin boundaries. A hydrogeological survey investigates a specific area's subsurface hydrologic and geologic parameters. The data gathered during such a study can be used to create hydrogeological maps. It entails a survey of the water-bearing levels as well as filtration capacity of rocks. Furthermore, the inherent ability of rocks to store or resist water is also evaluated. The pressure, category, and quality of groundwater are all recorded, as is the intensity of the water flow through pores or fractures. Hydrogeological survey reports have been conducted in the study area to understand better the local geology, geomorphology, drains network, aquifer qualities, and well yield.

What is Hydrogeology

Hydrogeology is the branch of geology concerned with the dispersion and groundwater movement in the earth's crust's soil and rocks, most commonly in aquifers. As a result, various components influencing the hydrogeological regime of the study area have been investigated. Underground water systems are formed by the complex combination of different depositional and institutional types within an area, creating an aquifer where groundwater moves and accumulates. The district's hydrogeology varies significantly depending on the geomorphological and geological setting and soil characteristics.

The Importance of Hydrogeological Survey Report

To determine the underground water level, such as in case of drilling a borewell, a hydrogeological survey is performed to determine the and quantity and quality of water available at a specific location. Underground water has long been recognised as a superior source of drinking water as compared to surface water. This is because of the following factors:

1. Lower pollution risk, especially if it is away from sanitary work.
2. Groundwater gets naturally purified
3. as water flows through sand and stone.
4. The possibility of contamination is reduced as borewells remain closed.
5. Regardless of the season, the water temperature is always desirable.
6. Summer has a higher chance of water availability because the water sources are located at a deeper level.

Groundwater is a sustainable option that could solve a water crisis for specific regions in the current situation, where pure, unpolluted water is scarce. However, determining the amount and quality of accessible groundwater at the requisite location can be difficult. Hydrogeological survey methods can recognise groundwater sources and predict produce and water quality. The assessment of the subsurface layer of rocks also facilitates the assembling of critical information about the future utility of groundwater. As a result, a hydrogeological survey report is required to provide sound recommendations for borehole drilling that will aid in acquiring high-quality groundwater for human consumption.

Component of Hydrogeological Survey Report

Typically, the hydrogeological assessment may be basic or complete. A basic survey includes the following:

1. Determination of end-requirements users for the location and quantity of groundwater required.
2. Assessment of groundwater quality
3. Evaluation of the catchment area
4. Borehole design and construction recommendations
5. Risk assessment for health or the environment
6. The amount of groundwater expected from the given location

CGWB is tasked with performing hydrogeological mapping assisted by groundwater exploration, geophysical assessments, aquifer parameter assessment, groundwater prediction, and groundwater regime monitoring. CGWB has amassed a massive database of water levels, water quality, underwater lithological and geophysical logs, and aquifer parameters through its research. The database analysis enabled the creation of hydrogeological maps and groundwater planning processes, in which the aquifer-wise area suitable for groundwater recharge, development, and preservation was identified.

Types of Hydrogeological Survey report

Depending on the purpose of the procedure, the hydrogeological survey can be conducted on a large, medium, or small scale. First, existing research data from private and government agencies are evaluated, accompanied by comprehensive field research as needed.

To assemble preliminary information on the hydrogeological condition, a small-scale hydrogeological survey (1:1,000,000-1:500,000) is conducted in regions that have never been investigated before. These include information on the ability of the rocks in the area to water retention and the overall quality of the underground water. Medium-scale surveys ((1:200,000-1:100,000)) are more detailed and are used to collect data for hydrogeological mapping. Water-bearing structures are mapped, and a detailed study of the region's rock retentive capacity is carried out.

Large-scale hydrogeological surveys (1:50,000 and larger) are typically initiated to address specific issues during the engineering and operational planning stages. This survey identifies areas where water can be collected and investigates underground water reserves. Drilling processes, assessment of the composition and quantity of underground water, and proper flow measurement are also required for large- and medium-scale assessments. Construction of wells and pumping tests may be performed to understand the hydrogeological condition thoroughly.

Scope of the Hydrogeological survey in India

The scope of the Hydrogeological survey includes:

• Site visits to become acquainted with the project areas. Determine any problems that may arise as a result of planned mining activities that may have an impact on the Ground Water Scenario.
• Acquire, research, and synthesise background information such as geology, hydrography, and established borehole data to improve assessment quality and plan detailed hydrogeological reports.
• To conduct hydrogeological and geophysical research in the sample locations to determine the groundwater potential at the development site.
• To prepare hydrogeological survey reports by the guidelines of the Central Ground Water Board's rules and procedures, by assessing the quality of the water and potential violations of national standards, assessing groundwater presence, and assessing the consequences of the planned activity on the groundwater, quality of water, and other abstractors.

Structure of the Hydrogeological Survey Report

As previously stated, the content of a hydrogeologic report will vary depending on the project. Standalone hydrogeologic pieces should be well organised and include the majority, if not all, of the following elements:

• Page 1: Title
• Page 2: Signature Page
• Table of Contents Tables, Figures, and Appendices lists
• Introduction
• Hydrogeologic Systems: Their Purpose and Description
• Data Collection Methods
• Analysis of Groundwater Use and Development Methods and Procedures
• Hydrogeologic Evaluation
• Documentation of Numerical Models (if modelling is performed)
• Water Quality Findings
• Recommendations, if required
• Report Restrictions
• Sources of Information and References
• Appendices, tables, and figures

Information/Documentation needed

The hydrogeological survey report should include the following information:

• The goal and scope of the project.
• Documentation of Data Collection.
• Site Overview.
• Setting Geologic.
• Setting hydrogeologic.
• Surface Characteristics.
• Seismic Activity.
• Sources of information.
• Figures
• Tables of data.
• Impact on groundwater.
• Data collection in the field.
• Data interpretation and analysis.
• Methods and reports for laboratory testing.
• Hypotheses
• Conclusions
• Recommendations

How can Corpbiz assist?

Following a site assessment, we help create detailed hydrogeological survey reports for environmental monitoring, wellbore siting, or as part of current site investigations. Hydrogeological surveys are used to determine the depth of the subsurface water table.

We also help conduct a background review of previous site investigation reports and available published background hydrogeological reports, well records and geological mapping; review of geological and hydrogeological conditions present at the boreholes on the site.