Email correspondence between Tiffany and Fred re: the baffle spacing in floc tank b, the additional sed tanks, and a possible need for a surge chamber in floc tank a-
Tiffany's Email
Hey, I completely forget the spacing we ended up going with in floc tank B, was it 38cm oc?
also, how long exactly are the new sed tanks?
Fred's Response
I did a modest change on Flocc tank B to eliminate the wider baffle spacing at the end where A will connect. Used 40 cm on center for all but the last one before A which ended up being 34 cm. .Recaculated the over under baffle openings according to the 1.5 standard and marked all of the places for slots for insertion of the baffle plates when I return in mid February. The baffles are in A and they have all the sizes for C and I marked the top and bottom for them. They seem to understand how it will work once we got the baffles in A in place. The opening between a and B will be 25 cm.
The sed tanks ended up being 240 cm long by 102 to 104 wide. Due to the fact that we are on the low side for the sedementation I have decided to go ahead and construct one additional sed take in the second tank. They are going to cut the transition channel through the center wall and extend the transition channel to serve that tank. Everything will be sized the same as the origina sed tanks except that this one may be 265 meters long if that does not cause a problem. This will represent an approximate 25% increase in sed space. This will have one end ot the transition channel supplying two sed tanks and the other end three.
It is much easier to get this work done know bwfore the plant is in use so I decided to go ahead with it. If it creates a serious problem it can be plugged off. I knew we were on the low side for sed space then discovered that we lost 20 to25 cm of length when then mistakenly constructed an additional support wall at the beginning of the sed tanks. Apparently my plans were not as clear as I thought. The other reason for doing this additional sed tank now is that we finally located all the suppl piping from the water sources and I expect the flow may slightly exceed the design 500 gpm. Nick was here this week and the Alcaaldia employees field located all the lines and Nick confirmed that the both ot the souces are high enough to feed the treatment plant. Actually we figured out a way to use both of the supply lines and the Alcaldia will only have to construct about 250 meters of new pipe.
Construction has gone well this past week and the chem platform is conplete and I was able to walk up a good set of stairs this morning to reach the platform level. The chem tank tank platforn will be constructed this coming week and the floors in the three remainging flocc tanks will be poured.
I would like to use the first 14 inches of flocc tank A for a surge chamber to be constructed with 4 inch block with a lot of two inch openings in bottom half to assure that water force will be evenly dispersed and not hit the flexable baffles too hard. What do you think?