White billowy foam and thick brown foam look alike in a photograph and mean opposite things. Field notes on what we found underneath each one, and the order we work through it.
Your STP can pass BOD and TSS and still fail ammonia, because the bacteria that remove ammonia are slow, alkalinity-hungry, oxygen-hungry and easy to kill. Field notes on the four things that quietly wipe them out, the food processing plant where I created my own nitrification problem with one piping decision, and what I check before anyone orders more bacteria.
Bacteria dosing is a real tool for commissioning, restarts and shock recovery. It is not a fix for low DO, solids washout, short retention time or an ongoing toxic input. Field notes on when I recommend probiotics for a sewage treatment plant, when I refuse to, and the food processing plant that taught me the difference.
After years of designing and operating treatment plants around Cebu, I've learned that how dirty wastewater looks tells you almost nothing about how hard it will be to treat. Here's what actually makes a stream difficult, from someone who learned it the hard way.
Cebu City's July 30-31 flooding submerged 16 barangays - and dozens of sewage treatment plants nobody is talking about. A field guide to what floodwater does to an STP, what to check before switching everything back on, and the design lessons every flood keeps teaching us.
