Quality, Standards and Testing

The subsurface aquifer systems in Mahanadi delta region in Orissa (India) is largely characterized by two groups of freshwater aquifer systems, both of which are prone to saline water mixing/migration with time and development:

• The south western Mahanadi delta region is represented by unconfined to semi-confined freshwater aquifers underlained by brackish/saline aquifer systems with a diffusion boundary.
• The north eastern parts of Mahanadi delta is represented by deep freshwater confined aquifers overlained by brackish/saline water aquifers with aquitard/ aquiclude boundary.

The study provides an analysis of groundwater quality to identify probable pollution or contamination in coastal aquifers of Kakinada in Andhra Pradesh. Sampling surveys have been conducted in the months of May 99, August 99 and November 99 and about 186 water samples were collected from shallow wells, filter points, canal water and rainwater. The spatial and temporal variations of water quality parameters are presented in the report. 

The report provides an account of the findings of water quality studies of Lake Nainital and surroundings. Even though quite a few water quality investigations have been conducted by other researchers, they were more focused on biological aspects and overlooked the hydrological aspects. Further, not all of the earlier studies on Nainital incorporated the groundwater quality aspects, which are essential to establish the background values that can be ascribed to the geology of the region. Only after establishing these, the pollution levels can be assessed.

The study attempts water quality monitoring of Mansar lake to detect the various water quality parameters. The lake water conditions were monitored by collecting water samples from different depths to determine the spatial and temporal variations.

The report deals with the findings of a water quality study of Mansar lake in Udhampur district of Jammu and Kashmir. The water samples from different locations at the surface and from three zones (viz, epilimnion, metalimnion and hypolimnion) were collected and physico-analysis carried out.

The study presents detailed investigations of the chemical quality of groundwater in Jammu and Kathua districts (J & K), carried out to evaluate the suitability of water for various uses. The quality of groundwater of the area has been studied based on the physico-chemical analysis of thirty seven water samples collected from open wells between June and December, 1996.

Various parameters like pH, conductance, alkalinity, hardness, chloride, sulphate, sodium, potassium, calcium and magnesium have been determined for all the samples and compared with the standards to evaluate its suitability for drinking and irrigation purposes.

Irrigation water quality has been computed on the basis of Doneen’s Permeability Index and residual Sodium Carbonate. The higher values of some parameters at certain locations indicate the contamination in groundwater and make the water unsuitable for specific applications.

The report presents a methodology to assess the probability distribution of Dissolved Oxygen (DO) based on the Streeter-Phelp’s equation. The methodology involves the use of first order analysis and Monte Carlo simulation to analyze the uncertainty associated with DO. The mean and standard deviation of the parameters have been assumed as same for the study’s probability distributions.

The study presents a status report on hydrological problems of hard rock areas related to hydrological network design, groundwater quality, failure of open and borewells, regional flood formulae, groundwater balance studies, reservoir sedimentation, hydrological aspects of droughts, forest hydrology and drainage problems of black soil of the hard rock terrain.

The study evaluates groundwater on the basis of widely used graphical methods like Piper, Stiff and US Salinity Laboratory classification. The study concludes that, in general, the groundwater in the area varies from medium salinity to very high salinity, the latter being more common in the irrigated stretches. The irrigators are advised to ensure good land and water management practices in the fields, with particular emphasis on creating favorable leaching and drainage conditions to avoid further development of saline conditions in the area. 

The study applies geostatistical techniques to the groundwater quality data of December 1994 in parts of Jammu district. Groundwater quality deterioration has led to considerable interest in the design of investigative studies and monitoring programs on the issue.

Various management measures need to take into account the spatial and temporal behavior of groundwater. The spatial dependence between observations can be expressed by semi variance, which is a measure of the average similarity between observations at a given distance apart. One of the prime reasons for obtaining a semivariogram is to use it for estimation of the variable at unsampled locations.