Aquifer Sensitivity to Nitrate Leaching in Illinois

Aquifer Sensitivity to Contamination by Nitrate Leaching in Illinois is a statewide geospatial dataset evaluating shallow aquifer vulnerability. SCIOPS created it by combining a soil association map and a geologic stack-unit map to classify sensitivity into six categories. The data was published in 1995 at a nominal scale of 1:250,000.

Use Cases

• Classify soil nitrate leaching potential using soil association map factors related to water movement.
• Map depth to the uppermost aquifer using the geologic stack-unit map to a depth of 50 feet.
• Generate a combined aquifer sensitivity map with six classes: Excessive, High, Moderate, Somewhat limited, Limited, and Very limited.
• Identify disturbed land and surface water areas as part of statewide environmental assessment.
• Evaluate shallow aquifer contamination potential in conjunction with the ISGS Environmental Geology report 148.

Strengths

• Statewide coverage for Illinois provides a complete regional assessment.
• Integrates two foundational statewide datasets: soil association maps and geologic stack-unit maps.
• Defines six distinct aquifer sensitivity classes for granular analysis.

Limitations

• Classifications are from 1995 and have not been validated by subsequent water quality sampling.
• Data reliability as a predictor of actual water quality has not been evaluated.
• Source map scales vary (1:15,000 to 1:250,000), but the final product is published at 1:500,000.

Provenance

Source

SCIOPS

Collection Method

Interpretive mapping model combining a soil association map/database and a geologic stack-unit map.

Freshness

Last updated in 1995; no updates indicated.

Geography

State of Illinois, USA.