Hillcrest Elementary School added another jewel to its tiara of crowning achievements last month.

An emerald.

Hillcrest Elementary received the Best of Green Schools award from the Center for Green Schools at the U.S. Green Building Council March 22, at the Green Schools Conference and Expo in Atlanta, Ga.

The award was bestowed upon the much-lauded primary school in the “Student Leader” category, given in collaboration with the Green Schools National Network.

Hillcrest has been a National Green Ribbon School since 2015. This year, the school decreased its waste production by 75 percent and lowered its waste-hauling costs by 50 percent, according to the school district.

To accomplish this, Hillcrest switched its school lunch trays from Styrofoam to compostable materials.

The school also has a chicken-raising program and a covered outdoor classroom.

Each year, 11 individuals, institutions, projects and events — which represent the best environmental efforts in schools across the country — are recognized in the Best of Green Schools awards.