Here's a starting point (PDF document). Your BOD/COD will not really be influence by your filtration. If you have a compressor, you should sparge liquid waste with compressed air going into the holding tank (helps lower BOD). Volumes - estimate 8:1 is a reasonable start point (8 volumes water for every volume beer produced) especially on your small scale. Easy to track this number based on water meter readings and recorded production numbers.
Don't worry about low levels of chlorine. When your local municipality comes to sample, insist on a 12 or 24 hour composite sample (done with an auto sampler) instead of just a 'grab' sample. 'Grab samples' are notoriously unreflective of your true effluent situation.
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Last edited by liammckenna; 11-10-2011 at 03:15 AM.