Retorts No. 27 and No. 28 continued to burn through the first quarter of 1984. Stability problems in the electrical supply system were corrected by the first week of January. Through the second and the third weeks of January, air injection rates were increased substantially. Combined oil production rates for the two retorts averaged as high as 330 barrels per day. Production remained stable through the first six days of February. Electrical problems were responsible for reduced air-in rates through February 14. Mid retort off gas piping and oil production pumps were removed from Retort No. 27 during the last week of February. Modifications were made to the off gas system between the demister tanks. As a result, the pressure drop through the system on the vacuum side was reduced, and gas flow through the gas processing plant was increased. The ammonia and hydrogen sulfide removal plants were put through the initial phases of start-up during late January. The hydrogen sulfide plant was shut down for most of February so the sulfur melter circuit could be remodeled. The plant was tested and returned to service during the last week of the period. The ammonia removal plant was in operation most of February. During March, the hydrogen sulfide absorber column in the ARI plant became plugged with elemental sulfur. Repairs and cleaning were underway by the end of the period.