At Croatian food producer Belje’s dairy factories, remains of whey represent a burden in waste water, making the treatment of waste water very expensive. Belje is now partially shipping whey, a by-product in its dairy plant, to biogas facility. Whey is also partially used as wet feed on pig farms. Annual production of whey is roughly 55 thousand tons. Currently, 10% of Belje’s annual production of whey is used in the bio-gas plant and 90% is used as pig feed. By directing whey to re-use Belje achieves 70,000 Euro of savings per year.