Record phosphorus amounts removed from local watershed in 2017

The Madison Metropolitan Sewage District shipped a record volume of phosphorus out of the watershed in 2017, according to a release.

The phosphorus is shipped out as tiny pellets of struvite fertilizer, known as Crystal Green. In 2017, MMSD produced 585.1 tons of struvite, up from 497.7 tons in 2016. That equates to 146,000 pounds of pure phosphorus in 2017, and a single pound of phosphorus can lead to 500 pounds of algae.

Biogas production also surged, from 269.9 million cubic feet in 2016 to 305.1 million cubic feet in 2017. The biogas generated more than 7.4 million kilowatt-hours of electric power to offset MMSD’s own energy use.