Nebraska Administrative Code
Nebraska Department of Environment and Energy

Title 118 - Groundwater Quality Standards and Use Classification
Attachment B - Recommended Information Requirements for Step 7 Assessment



Note: A Detailed Site Assessment (Step 7) is performed in addition to, and possibly in conjunction with, the Initial Site Assessment (Step 6) if ground water contamination is identified, suspected, or imminent).

I. Aquifer(s)
A. Hydrogeologic framework of principal (regional) aquifer
1. Thickness
2. Transmissivity
3. Lithology
4. Faults, fractures and other secondary permeability characteristics (if present)
5. Approximate water-level elevation or depth to water
6. Overlying (perched) aquifer and underlying confined aquifer (if present)
7. Geologic formation name(s)
8. Regional flow direction(s)
9. Flow velocity

B. Uppermost aquifer
1. Configuration of the water table
2. Thickness of each stratum
3. Lithology of each stratum
4. Permeability or transmissivity
5. Flow velocity
6. Local sources of recharge and/or discharge (e.g., losing and gaining streams)

II. Ground Water Contaminant Plume
A. Lateral and vertical configuration
B. Quantity and/or concentration of contaminant(s)
C. Velocity of movement

III. Ground Water Use
A. Identify all water supply wells within 2,000 feet of thecontaminant plume

B. Well inventory data
1. Location (legal description)
2. Use(s)
3. Depth
4. Owner
5. Construction specifications

IV. Background Quality of Ground Water
A. Uppermost aquifer
B. Principal aquifer (if distinct from uppermost aquifer)
C. Water-quality parameters
1. Dissolved solids content (or specific conductance measurement)
2. Nitrate-nitrogen
3. Primary chemical constituents of material discharged

V. Site Characteristics
A. Climatic information
B. Topography
C. Accessibility
D. Land Use
E. Existing or abandoned wells or test holes not identified in III above within 2,000 feet of the contaminant plume

VI. Reporting Requirements
A. Detailed test hole logs
1. Thickness and lithology of all strata
2. Measured water levels
3. Land surface elevations
4. Other pertinent information

B. Map(s)/Cross Section(s)/Table(s)
1. Large-scale site map showing pertinent features and location of test borings and inventoried wells and/or test holes.
2. Map and cross section(s) depicting contaminant plume
3. Water-table-configuration map
4. Results of field/laboratory analyses

C. Text describing and analyzing information