“Lubao experiences frequent flooding and storms, and access to clean water is limited.” Melody’s answer is a bioretention cell — an engineered rain garden designed to pull nitrate-nitrogen out of stormwater before it reaches the community’s water.

“A bioretention cell with a 30-inch deep subsurface saturated zone and an upturned elbow hydraulic control — containing a carbon-augmented substrate of coarse sand, coconut coir, and hardwood mulch, planted with Vetiveria zizanioides, Fimbristylis miliacea, and Canna indica — will cause a statistically significant decrease in nitrate-nitrogen (NO₃-N) concentration in the effluent compared to the influent runoff.”

What she’s built

• A fully specified cell (8′ × 4′ × 30″): a 10″ saturated zone of crushed stone and coconut husk, a choker layer, 10″ of sand/topsoil/coir filtration media, mulch, a 6″ ponding zone, and 4″ perforated PVC with an upturned elbow
• Two complete water-testing protocols — simulated-storm hydraulic loading with spiked drums, and natural-rainfall first-flush sampling with cold chain and chain of custody
• A lab plan (ion chromatography at Philippine labs including DOST RSTL III) across a minimum of 10 rain events, analyzed with a paired t-test

The design and protocols are complete; Melody is raising $5,500 (total budget $6,440, including $1,500 of lab analysis) to build and test the cell.

Meet the fellow

Melody Zheng is in the Fellowship’s Engineering track. Her bioretention cell is fully engineered — media layers, hydraulic controls, and planting palette all specified — with two complete water-testing protocols (simulated-storm and natural-rainfall) and a laboratory analysis plan spanning a minimum of ten rain events.

This project is part of Eat The Elephant’s work in Lubao, Pampanga — explore the Lubao project hub →