What an Inspector Opens First: Six Records Behind a Leachate File

An inspector arriving at a leachate solidification pad rarely starts with the plant. They start with a folder, and the first thing they read is the batch log. If the arithmetic in that log reconciles with the waste transfer notes and the polymer purchase ledger, the visit tends to be short. If it does not, the visit gets long and expensive, regardless of how well the plant is actually running.

The Six Documents That Get Asked For

Waste characterisation. A laboratory report on the leachate itself, no more than twelve months old, with sampling point, date, and the parameters that justify the treatment route: pH, total dissolved solids, chloride, ammonia, COD, and the metals panel your disposal site requires. Re-characterise whenever the source cell changes, because an ageing cell at 12,000 mg/L TDS and a young one at 40,000 are different wastes on paper as well as in the tank.

Chain of custody. Sample identity, sampling point, time, preservative, transport temperature and the receiving laboratory’s acknowledgement. Metals go into nitric acid, ammonia into sulphuric, and both need to arrive cool. A result without a custody record is a number, not evidence.

Batch treatment record. Date, start and finish time, source sump, volume treated in cubic metres, polymer grade and lot number, kilograms added, operator name and signature. This is the document that gets cross-checked, so the units need to be unambiguous and the volumes need to come from a gauge rather than an estimate.

Verification result. The test that shows the output meets the receiving site’s specification, run on a sample from that batch and tied to it by batch number. One result per batch, or per 200 cubic metres where batches are large and homogeneous.

Transport documentation. Transfer note or manifest with container count, net mass, carrier registration, destination and the non-hazardous or hazardous classification. Solidified material that still carries a liquid-waste description is a paperwork failure even when the drum is bone dry.

Disposal acceptance. The receiving facility’s weight ticket and acceptance confirmation, filed against the outgoing load. Without it the trail stops at your gate.

The Numbers Behind the Signature

Most acceptance specifications reduce to a short list. No free liquid by paint filter test, judged at five minutes. Moisture at or below 70 percent by weight for non-hazardous landfill, 65 percent for many monofills, measured by oven drying at 105 °C to constant mass. pH between 2 and 12.5 if the site applies a pH window. Leachable metals below the receiving site’s limits by the toxicity characteristic procedure, or the equivalent method named in your permit. Stackability after 24 hours if the material is to be placed rather than bulked.

Record the method alongside the result, not just the pass. An inspector who sees a moisture figure of 64 percent with no method will ask how it was determined, and if nobody can say, the whole table becomes provisional.

Where Files Actually Fail

The common failure is not a bad result; it is a small inconsistency that suggests the records were reconstructed after the fact. Three examples come up repeatedly. A monthly polymer purchase of 4.2 tonnes against batch records claiming 6.8 tonnes consumed. Verification results in the same handwriting as the batch log, signed by the driver. Photographs of paint filter tests with no date stamp and no batch card in frame.

Two habits prevent all three. First, write the batch card at the pad, in sequence, with the polymer lot number copied from the bag at the moment of opening; never transcribe a week later. Second, keep a deviations log and use it. A page that records a batch 214 dosed at 1.4 times, gel still soft, re-dosed 40 kg, passed on retest is worth more in an inspection than twelve months of untroubled passes, because it shows the process responds to evidence.

None of this depends on which polymer you buy, but the data you can hand over does depend on the grade being consistent from lot to lot, which is why lot numbering and retained samples matter. Documentation and product specification for the grades used in this work are set out on the leachate solidification grade pages.