Wastewater

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.

Small STPs fail more often than large ones, and not because they are cheap. Field notes from Cebu on why 5 cubic meters a day is harder to operate than 500 — and how I design small sewage treatment plants differently now.

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.

Field notes on water reuse in the Philippines: why reuse projects die on the spreadsheet, what the second pipe really costs, the honest cost per cubic metre, and when reclaimed water is actually worth building.