eorereeTn. JOHNSTON ATOLL SUPPORT 02069 Page 2 A 16-inch wide, grating-covered trench, for collecting runoff water will extend the entire length of the decon pad along the west side. From this trench, uncontaminated water runoff will be gravity drained directly to the lagoon north of the west wharf. The contaminated water originating from the aircraft wash down operations will be bypassed to a sump pit adjacent to a 6000-gallon reinforced concrete and plastic-lined holding tank. A sump pumpwill elevate the contaminated water into the holding tank. When the radioactive decay of the contaminated water has progressed satisfactorily, and the tide conditions in the west channel are favorable, the contaminated water in the holding tank can be released into the lagoon by opening a 6-inch valve. The uncontaminated and contaminated water are emptied into the lagoon via the same drain line. All existing facilities within 60 feet of the decontamination facility must be removed or relocated. OP WH * This estimate includes: A new substation Resiting of Building 950 Blast paving of shoulders Relocation of Asphalt ‘Plant Post-GO Procurement 2-63 VOLI