High-tech protective liners are being put under a former landfill in Lake Elmo to prevent further groundwater pollution. Workers are excavating and refilling different segments, or cells, of the landfill in stages.

1. Trash from the first cell has been piled in a mound as workers install the liners.

2. Trash from the second cell will be moved to the first when it is finished. Liners will be installed in the second cell as it is emptied.

3. Garbage from the third cell will be placed in the second, and work will proceed until all six cells are lined and filled.

The work should be done by the end of 2011. When finished, the landfill will be underlaid with compacted clay, liners and a leachate collection system.

TOM MEERSMAN