Friday, August 12
By 7:15 am we were on the dredge preparing for the day. Moving around on the dredge is a careful dance among a tangle of hoses and gear, and we are always looking for ways to make things more organized, comfortable and safe. After moving the water pump yesterday, Timmy decided we could use less hose curled on the deck, so he shortened the water pump intake hose and cut our wash-water hose in half, enlarging our ohso- limited free deck space.
Around 8 am we started pumping and one trip across the canal and back took 2 hours. We are reaching the limit of the discharge hose at our current configuration and will have to move the dredge to a new part of the canal next week. We shut down early because of impending storms.
With thunder growling in the distance, we made a quick visit to the test site. With low water, the fill was again exposed, and there was green growth everywhere! Spikerush (Eleocharis sp.) is spreading rapidly to cover the mud surface, and the Bacopa that we tossed in over the last few weeks is spreading to make nice clumps. Three-square (Scirpus olneyi) is sending runners along the perimeter in several areas. The Spartina alterniflora planted along the inside of the containment has become quite lush.
The mud has settled into a thick, cohesive, stabile substrate, and by the walkway it is roughly 6-8 inches deep. The reed containment is full of mud and water, and is starting to decompose inplace as expected. With the vegetation growing along and in it, it should remain a barrier for mud retention for a while longer yet.The threatening weather was still bypassing the work area, so we had time to visit the experimental site. The low water conditions and the fluid mud in Cell 4 kept us from getting very close to the discharge by canoe, but we were able to check out the extent and direction of the finer particle plume.
The mud plume was throughout Cell 4 and extended into all other cells. The main plume from the current outfall was directed toward the south shore of Cell 4, and it was obvious that there was fine grain sediment escaping through the reed containment 4c and 4d since the water in the greater pond on this side of SAVs was almost the same color as that of Cell 4. However, we were unable to locate a large enough break in the larger containment 4c to account for that much of a plume.
To the left of 4c is the smaller containment 4d, which also appeared to be intact and performing well to block the flow. However, to the left of the containment, we could see that there was water flow into Cell 4, diluting the muddy water.
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