Their oldest manufacturing campus has 90% of its 200 billion dollar revenue going through its manufacturing cells. Unfortunately, in its day, the architects decided to make the roofs out of copper to empathize with the power of this metal. Now, 53 years later, they are realizing their mistake in the material selection.
At least the contractors’ warehouse buildings are of galvanized roofing; however, it is a problem for zinc. This is where the Manufacturer’s environmental consultant placed its initial emphasis. They researched different systems and decided to put a Gullywasher’s upflow biofilter to the test.
In 2014, they bought one 55 BioUP biofilter for pilot testing. Not only did the zinc concentrations drop from the 4.5 ppm range to that of 0.009 ppm levels; but the flow capacities outperform the previous system that the consultant had pilot tested. Due to the pilot testing success, they purchased a second one to see whether the biofilter performance could be duplicated, and it did. The Upflow biofilter performed beyond their expectations, again!
In 2015, the consultant led a study, to see whether less expensive biochar media mixes or compost media, could be used. All three-test media failed to last even for 2 months; whereas, the current Gullywasher M2 biochar mixture produced a consistent 99.97% removal of total & dissolved zinc! See the results on the table below.
After looking at these results, the manufacturer purchased 14 – 55 BioUP biofilters for their west campus in Y2015 & Y2016.
The Gullywasher biofilter effluents were so low that the consultant decided to utilize this effluent water and mix it with the surface water from the west campus. This eliminated the need for the surface water to be filtered/treated. The blended water was and is still under the 0.120 ppm benchmark compliance limit for zinc.
The manufacturer has also installed 3 more 55 BioUP biofilters and a 275 BioUP biofilter in their east campus in order to take care of some copper hot spots in the roofing. Again, with excellent results.
These Biofilters are still on-site and still achieving compliance after 6 years of use. The media of these filters are change in a yearly basis to achieve numbers so low that they can blended with the untreated surface water and still be in compliance.