There are common hotspots in a craft brewery that are major contributors to volume of water used and wastewater strength (BOD and TSS). Click on the image below to see these hotspots. They represent areas where craft brewers can focus and prioritise their efforts to be more water efficient and to keep stuff out of the drain.
Hot Liquor Tank
Clean Water In
The frequency of cleaning along with the challenges of cleaning the various brewhouse components make this a major water use point.
Residual spent grains and trub that are rinsed from tanks and down drains are a major source of solids.
Disposal of spent yeast (containing beer and yeast solids) to the drain from fermenters is often the largest single contributor to BOD.
Sending yeast solids from fermentation tanks down the drain can be significant contributor to TSS.
Backwashing or cleaning filters into the drain results in all the filtered organic material as well as DE ending up in the wastewater.
Diatomaceous earth, along with all the solids it filtered from the beer, can be a major source of solids if it is disposed of down the drain.
Cleaning and rinsing equipment, returned kegs and bottles, and filled containers can use significant quantities of water.
Over-fills, foaming, spills, and the emptying of mis-fills or returned product to the drain can result in high BOD wastewater.
These are generally good places to start when looking for improvements that will have the most impact, but every brewery is different.