Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

L. Clayton


The data from this study can be applied to much of southwestern North Dakota because the geologic and climatic conditions are similar.

The Mandan landfill is on the Heart River floodplain and next to the river on the north and steep valley wall on the south. The sanitary landfill bas been used for over 20 years.

The only pre-Pleistocene unit exposed is the Cannonball Formation, which is interbedded sand, silt, and clay. Quaternary units consist of till, fluvial sand, silt, clay, and gravel, and eolian sand and silt.

A local flow system recharges on the upland next to the valley and discharges in the valley. Flow is mostly lateral and toward the river. An intermediate flow system discharges in the Missouri River valley and many receive seepage from local flow systems.

Shallow groundwater near the landfill is generally a calciumbicarbonate type. Deeper groundwater is generally a sodium bicarbonatesulfate type.

Shallow groundwater has been contaminated by landfill leachate. Greatest changes in groundwater occur near the center of the landfill, where there are increases in calcium, magnesium, total hardiness, bicarbonate, total alkalinity, total dissolved solids, and chloride and decreases in sulfate and pH.

Leachate production is low because of lack of moisture, low temperature, and large amounts cf cellulose-based refuse. Recharge rarely occurs, but some parts of the landfill receive enough moisture. From groundwater and infiltration to produce leachate. The greatest amount of decomposition (mostly anaerobic) occurs soon after burial.

Included in

Geology Commons