Resource Description: NODC Accession # 9900012
Sediment throughput samples were taken at Units 1-4 and 5-6 discharge points within the Kahe outfall transition basin (Figure 1). Samples were collected by placing a 0.25-m diameter plankton net directly in the discharge. The 110 m mesh plankton net was held approximately 10 m behind the discharge ports for at least three minutes at a depth of 0.5 m. Flow rates determined with a General Oceanics digital flow meter were then used to calculate the total volumes of water sampled. Samples were collected four times in 1996, including two periods of medium to high surf. Pertinent data relating to weather and sea conditions were recorded. Measured amounts of suspended sediment were converted to units of ml/m3 by dividing by the total volume of seawater sampled. These were then extrapolated to daily throughput estimates by multiplying by the volume of cooling water circulated under operation of all six generating units (3.257 x 106 m3/day).
For bed load sediments, HECO operations personnel conduct pumping and record dates, durations and pumping rates to enable calculation of the total volume of sediment pumped from the forebays. Contractors are hired occasionally to pump or dredge sand from the forebays, intake or discharge basin, during which sand removal volumes are based on contractors' estimates. Whenever sediment was dredged, the volume removed was estimated by the number of truck loads required to transport the sediment to its deposition site.
Photographic transparancies of coral coverage at each quadrat were projected onto a white surface on which a rectangle had been drawn which corresponded to the camera stand's 0.66 m2 quadrat. The projected image of the camera stand quadrat was adjusted in size and position to assure a consistent projected area and view of a station's quadrat area between sampling years. Each photo-quadrat slide represents a permanent record of the condition of the coral reef at the time the photograph was taken.