earthquake activity.

Situation after an earthquake will bring serious harmful effects on groundwater. New moved state of

the layers will be unknown picture about quantitative and qualitative character of the groundwater

reservoirs. The following faults are potential disaster for the shallow and deep groundwater. Now

the shallow groundwater in many cases is severely contaminated by human, industrial and

agricultural wastes. But deep groundwater is the future source for water supply.

The importance of groundwater is vital too much of live on Earth, because the groundwater

represents around 30% of freshwater resources of the earth, while lakes and rivers correspond to less

than 1% and the largest volume of freshwater is stored in glaciers (69%).

A significant part of the World’s countries suffer from shortage of good quality drinking water

supply. The need for more careful management of our planet’s water resources is growing because

of the growing demand of the growing population.

The future development of many countries will depend decisively upon how the increasing demand

for water will satisfied and how the economic and environmental cost for that demand may be met.

Hence, protection of soil- and groundwater resources against depletion and degradation has

developed into one of today’s foremost problem worldwide.

Future generation must be guaranteed sufficient water supplies free of health risks through regulated

use and protection against contamination of groundwater resources.

Groundwater contamination can originate on the surface of the ground, in the ground above the

water table or in the ground bellow the water table. Given table shows the types of activities that can

cause groundwater contamination at each level.

Infiltration of polluted surface water

Land disposal of wastes

Stockpiles

Dumps

Sewage sludge disposal

De-icing salt use & storage

Animal feedlots

Fertilizers & pesticides

Accidental spills

Airborne source particulates

Septic tanks, cesspools, & privies

Holding ponds & lagoons

Sanitary landfills

Waste disposal in excavations

Underground storage tank leaks

Underground pipeline leaks

Artificial recharge

Sumps and dry wells

Graveyards

Waste disposal in wells

Drainage wells and canals

Underground storage

Mines

Exploratory wells

Abandoned wells

Water-supply wells

Ground-water withdrawal

landfills and agricultural activities.

cesspools and privies.

Big part of homes rely on septic systems to dispose of their human wastes.

In these systems are, improperly sited designed constructed or maintained, they can allow

contamination of the ground water by bacteria, nitrates, viruses, synthetic detergents, household

chemicals, and chlorides. Although, each system can make an insignificant contribution to

groundwater, contamination the sheer number of such systems and their widespread use in every

area that does not have a public sewage treatment system makes the serious contamination sources.

Case of Bulgaria (Fig.1), many homes situated on the Black Sea coast use septic tanks, which are

improperly constructed.

Earthquakes caused remarkable landslides on that coastal areas (the depth of the sliding surface vary

between 5-20m, the road is interrupted, some tens of houses, electrical and sewerage systems are

destroyed), that followed contaminated shallow groundwater. This water was a source for water

supply.

Deep groundwater is polluted by underground storage tanks. Between five and six million

underground storage tanks are used to store a variety of materials, including gasoline, fuel oil, and

numerous chemicals.

A particularly dangerous source for deep groundwater contamination is the disposal of nuclear

waste (Fig.2), if adequate measures are not designed and implemented.

Facilities constructed on unstable ground are at greater risk for landslides, which could cause

accidental hazardous waste releases.

Earthquake experts recommend a number of safety features for facilities in areas where earthquake

activity can cause ground sharing or ground repture:

- Design structures at hazardous waste management facilities to resist ground motion or

shaking and withstand the maximum horizontal acceleration value expected at the earth

surface in that particular area. It has been found that the horizontal direction of shaking

is much more damaging to structures than the vertical direction.

- Build structure containment systems to prevent spills in case of a failure.

- Pay special attention to site factors such as soil moisture and slope stability which may

enhance ground shaking and lead to structural failure

To prevent groundwater from contamination need careful management of waste disposal.

Hazardous toxic dumps should be located in an area, which is geologically stable.

Above ground systems can be monitored easily and remedies put in place quikly. With a below

ground site there is a real risk of “out of sight, out of mind” and the problem will not be noticed

until severe damage has occurred to groundwater systems.

We have a responsibility to future generations to safeguard their environment as much as we can.

subsurface processes are extraordinary slow, and harmful or

toxic effects may only become evident several years or decades after a contaminant release.

Rehabilitation of contaminated soils or aquifers – if possible at all – frequently requires many years,

or even generations.

REFERENCES

Jolankai G., Gayer J., Water related environmental problems, VITUKI Budapest, 1997.

Evstatiev D., Frangov G. & Varbanov R., Landslide activation along the Northern Black Sea Coast

– causes, consequences and lessons, Sofia, 1997.

Office of Underground Storage Tanks. Musts for USGS – A Summary of the New regulations for

Underground Storage Tank Systems. U.S. EPA, Washington. P.C., 1998.

Class 2V Waste Disposal Site Proposed for Wunda-Y, Chitty Road, Bakers Hill – assessment

number 1202, Perth 6000 – USA, Graham Smith, 1998.

Citizen’s Guide To Ground-Water Protection. U.S. EPA, Washington, P.C., 1998.