I'm looking for guidance on containment for a 15,000 gallon steel tank to store 25% sodium hydroxide. I have specified a double-wall tank in lieu of a containment bund. I received an inquiry from the tank supplier asking if a "tight-wrapped double walled containment" is acceptable in lieu of...
I'm designing bulk caustic storage facilities for an existing 2 MGD water treatment plant. The plant currently receives bulk caustic shipments in 50 gallon drums and dilutes it to 25% in a day tank prior to feeding. Client would like to switch to tank truck delivery, so the obvious solution is...
I'm designing a new 0.5 MG elevated tank, which will be filled from an existing distribution system by a 10-inch line. I need an altitude valve to prevent the tank from overflowing. I've seen two different arrangements:
1. A single-acting (one-way flow) altitude valve with a bypass check...
Construction cost estimating is not my forte. My go-to methods are RS Means and emailing reps. My firm attempts to compile bid price records from previous projects, which is extremely helpful when I find relevant items; however, I often find this resource lacking.
Most of the estimating I do...
What are your opinions on algae control in secondary clarifiers? Some of the alternatives I know/have heard of are:
1. Install a cover over the entire clarifier
2. Install sun shades for the effluent troughs only
3. Install an automatic brush/cleaning system
4. Increase manual cleaning frequency
I'm specifying an elevated tank repainting. Right now, I'm going with AWWA Interior Coating System #5 (ICS-5) for the interior wet area of the tank. ICS-5 consists of a zinc-rich primer and epoxy intermediate and finish coats. All paints must be ANSI/NSF Standard 61 approved for immersion in...
I'm working on a small surface WTP design. Instead of providing a pumped filter backwash system, we're looking at running a line from an on-site elevated tank and installing a flow control valve.
One concern I have is the flow control valve wearing out. It will have to provide a significant...
A client of ours is having a pretty bad FOG problem at its WWTP, which is causing a number of headaches. One such headache is the build up of a floating sludge layer that shows up in the anaerobic selector tanks (see attached picture...
I have one of those dreaded "intermediate high point" issues for y'all.
Our client recently replaced an older submersible wastewater lift station with a new one pumping into the same 14-inch forcemain. The forcemain has an several intermediate high points, and combination air/vacuum valves...
