Compliance troubleshooting

Ammonia, BOD, TSS and odor problems in a permitted lagoon system, worked from the symptom back to the cause.

Short answer

Most lagoon permit violations trace back to two root causes: short-circuiting and sludge accumulation. Ammonia, TSS and odor are usually symptoms rather than separate problems. A defensible investigation starts with current organic loading, what cell one is actually removing, and a profile of the sludge blanket.

Start from the symptom

What you are seeingWhere it usually comes fromStart here
Ammonia over limitNitrification capacity, cell-one BOD removal, or water temperatureRead the guide
Rotten-egg odorAnaerobic conditions, usually the sludge blanket or an overloaded cellRead the guide
Unexplained TSS spikesSolids resuspending from a blanket near the effluent structureRead the guide
BOD violationsOrganic overload, inadequate oxygen, or short-circuitingRead the guide
Winter exceedances onlyNitrification shutting down in near-freezing waterRead the guide

The guides

The sequence that holds up

  1. Get current loading. Pounds of BOD5 per day and per acre per day, against what the cells were designed for. An overload is a pretreatment problem, not an equipment problem.
  2. Measure cell one. The primary cell should remove on the order of 80 percent of influent BOD5. When it does not, every downstream cell inherits work it was not designed for.
  3. Profile the sludge. Volume, distribution and composition, and specifically whether it is concentrated at the effluent end. The method is in sludge judging.
  4. Profile dissolved oxygen. By depth and location, pre-dawn as well as midday. A cell can read fine at the aerator and be anoxic thirty yards away.
  5. Read the seasonal pattern. Exceedances that track water temperature point at nitrification capacity, not equipment failure.