The Rostrum

By MICHAEL J. BARCELONA
and JAMES P. GIBB

Groundwater resources in Illinois: a scientific view

WATER of sufficient quality and quantity to sustain economic development is a critical ingredient for the continued vitality and growth of Illinois. A sound economy demands carefully conceived energy, water and food resource policies for the state because these policies are interdependent and complex.

Federal government policy in water resources has often been marked by interagency duplication of efforts, politics and confusion. There are no less than 13 water-related agencies. The state government reflects the fragmented federal situation with at least seven agencies heavily involved with various aspects of water. As a result, wise management of water has suffered.

Federal and state water agencies have focused primarily on the protection and management of lakes and rivers. The public has been involved in policy issues relating to the recreational, transportation, industrial and drinking water uses of these surface water resources.

Groundwater supplies provide a major portion of the water needs for at least half of Illinois' citizens; yet, public awareness of the vulnerability of our groundwater resources and the need for their protection has only recently arisen. The situation at Love Canal, N.Y., in which several hundred families were evacuated due to acute health problems related to contaminated groundwater, is probably responsible for much of our current attention to groundwater issues. And, Love Canal is not an isolated case. All of the populous industrialized states, including Illinois, face similar seriously damaging threats to their drinking water resulting from inadequate land or water resource protection.

Waste impoundments, open dumps, discarded chemicals and improperly operated landfills have served as sources of contamination since they communicate with groundwater by the percolation of rainfall through the soil. Gasoline, industrial solvents and hazardous substances have been the most frequently identified contaminants. In 1979, the Michigan Department of Natural Resources published an assessment of their problem, noting over 500 sites of known or suspected groundwater contamination. Testing costs to evaluate the extent of known pollution at 268 of those sites approached $46 million. The report further identifies more than 50,000 sites where potentially damaging activities to the resource had been, or are currently being, practiced. New Jersey, New York, Massachusetts and California have problems of like magnitude and in the past four years, millions of people dependent on groundwater have been forced to abandon their wells.

What laws exist to prevent the deterioration of groundwater resources? At least five major pieces of federal legislation cover various aspects of land and water use and control the handling of hazardous or toxic substances. They provide a framework for the regulation of groundwater pollution sources at the state level. Yet, few of these laws have been implemented due to a general lack of knowledge of the origin, occurrence, movement and quality of groundwater. We would like to clear up some popular misconceptions about groundwater and make recommendations for

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sound groundwater management. Some common misconceptions are:

• Groundwater exists in flowing streams, lakes or caverns below the land surface. No! Wells in Illinois tap porous, water-yielding geologic formations called aquifers composed of limestone, sandstone or deposits of sand and gravel. Water fills minute spaces between the particles of these formations and moves slowly in response to gravity.
• Rivers and streams drain into the subsurface recharging groundwater resources. Wrong! In fact, the opposite is more frequently true. State Water Survey studies have shown that perennial streams in Illinois may receive 30-85 percent of their flow from groundwater discharge. Stream water quality, as well as quantity, is greatly influenced by groundwater inputs.

  Shallow groundwater is recharged by rainfall percolating through the soil to the water table. Very deep bedrock aquifers may be recharged from hundreds of miles away where the rock formations come near the surface. These recharge processes take place over long periods of time, years to decades. An example of this is the deep sandstone aquifers in Northeast Illinois which receive their recharge from rains in North Central Illinois and Southern Wisconsin.

• Illinois groundwater is limitless, pure and naturally protected from surface contamination. No! The slow recharge processes outlined above determine the quantity of water which can be withdrawn safely from aquifers. Pumping in excess of recharge rates can cause "mining" of the resource. Overpumping of the aquifers in Northeastern Illinois has resulted in a drop of the water table of over 700 feet in the past 50 years.

  Groundwater purity depends on both the recharge water source (perhaps rain from 10 to 1,000 years ago) and the reaction of that water with the soil and aquifer solids over long time periods. Though soil may act as a "filter" for some dissolved substances in groundwater, its capacity is limited. Once this capacity is reached, so-called "natural" purification processes may serve only to slow the travel of hazardous substances with groundwater.

• Groundwater resources can be rehabilitated after contamination or after "mining" occurs. Perhaps! Research on contamination and excess withdrawals is being done. However, those problems arise over long periods of time and there are few quick, painless solutions. Water-purification processes have been designed for specific types of contamination, but the economics of expanded treatment plants currently outweigh the costs of alternate sources of water. That situation is likely to change in the future when water becomes a more precious commodity; the future has arrived for the Southwestern U.S.!

  Every citizen affects the quantity and quality of groundwater in subtle, but powerful ways. The reasoned stewardship of our states' human, agricultural, energy and water resources demands the development of a coherent plan. The federal legislative framework exists; so, state and local government officials must be sensitive to present and future needs of Illinois' citizens in developing management policy. It should be one which both recognizes the current state of the resource and will be responsive to future problems.

We suggest three basic scientific and institutional activities essential to this effort.

• Understanding the role of groundwater in the hydrologic cycle is essential. Groundwater education based on fact is essential. Legislation which ignores groundwater or encourages abuse of the resource must be reviewed, revised or supplemented.

• Groundwater resources of the state must be evaluated on a comprehensive basis. Water use patterns, aquifer yield capability, water quality and the extent of existing groundwater contamination should be surveyed with a statewide or regional focus. Because of the Water Survey's 85-year data collection program, it has a better data base than most states. However, support is needed for scientific interpretation of the existing information and we lack data on the organic and viral constituents in groundwater.
• A comprehensive statewide water plan must be developed which integrates groundwater and surface water protection with total environmental management goals, such as hazardous waste management or energy resource development.

  Groundwater resource management and protection represents a complex problem which will call for increased public awareness and close agency cooperation.

Michael J. Barcelona and James P. Gibb are the respective heads of the Aquatic Chemistry and Groundwater Sections of the Water Survey Division of the Illinois Department of Energy and Natural Resources. They and their staff are currently involved in various aspects of groundwater research. The Water Survey, headquartered in Champaign, is on the campus of the University of Illinois.

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