SEPTEMBER 1968 PRELIMINARY PROPOSAL FOR CONTAINMENT COVER WAS PREPARED BY RocKY FLATS ENGINEERING. JULY 1969 FIRST CoAT OF FiLt MATERIAL WAS APPLIED. AUGUST 1969 FILL WoRK WAS COMPLETED, PAVING CONTRACT WAS LET. SEPTEMBER 1969 OVERLAY MATERIAL, SOIL STERILANT AND ASPHALT PRIME CoAT WERE COMPLETED. NOVEMBER 1969 ASPHALT CONTAINMENT COVER WAS COMPLETED. FouR SAMPLING WELLS Were INSTALLED.