Hanford landfill expanded, updated

RICHLAND – Change is under way at Hanford’s central landfill – the spot where vast amounts of low-level radioactive wastes have been disposed of in the last dozen years.

The landfill – the Environmental Restoration Disposal Facility – is being expanded and modernized with equipment unavailable when it opened in 1996. The modernization is due at least in part to problems discovered early last year. A former worker fabricated results of compaction testing, and a malfunction of a water collection system in the lining beneath the landfill went undetected for months.

This week, two machines with cleated rollers will begin compacting waste to make sure sinkholes don’t develop after a cap is eventually placed over the landfill. The compactors are equipped with global positioning systems to track how many times each part of the landfill has been compacted.

The new system will replace the former requirement for manual compaction testing.

“No longer will people have to suit up and go into the contaminated area,” said Owen Robertson, the project engineer for the Department of Energy.

Meanwhile, a new computerized system will monitor the leachate collection system in the landfill’s clay lining. Data will be transmitted by radio frequency to the computer, which will alert managers if it detects a problem.

The landfill was designed to have 10 disposal “cells.” A subcontractor, DelHur Industries, is working on the construction of cells seven and eight. Workers have dug up 600,000 cubic yards of soil and will dig up a total of 1.3 million cubic yards to finish the two cells early next year.

The cells will be 70 feet deep and measure a combined 500 feet by 1,000 feet at their base.