The morning after a stretch of monsoon rain passes, walk the furrows in your garden and you'll find spots where your foot sinks right in. Those are the places where water sits for more than a day. The ground under the compost bin you tucked into the corner is usually one of them. Whether a patch has drained or is still soggy can come down to a few inches.
How Alappuzha, India, Chose Its Ground
In the state of Kerala, in southwest India, there's a district called Alappuzha. It's laced with lakes and canals, and the Vembanad-Kol wetland there is on the Ramsar list, the international register of protected wetlands. When the rains gather each year, the place floods. Researchers looking for ground to bury household waste built up their map one layer of conditions at a time. How far is it from open water? How far from villages, roads, and farmland? Does it flood year after year? Does the land slope? How shallow is the groundwater? How quickly does the soil let water through? How densely do people live nearby? Ten conditions in all, laid one over another.
What was left came to 3.6% of the district's total area. Everything else was ruled out by water — groundwater too shallow, flooding when the rains came, or soil that sent water down too easily. And even the three candidate sites that made the cut came with a condition attached: each still had to pass a site visit and an environmental impact assessment.
Scaled Down to a Garden
A landfill may sound a long way from a vegetable patch, but the way you read water and soil doesn't change with the scale. The same things come up when you decide where to put a compost bin, a pit for food scraps, or a barrel of liquid fertilizer. Does water pool here? Is the groundwater shallow? Is the soil sandy or heavy clay? Which way does the ground slope?
Pile compost on a spot that holds water and the brown leachate runs straight out of the pile. The smell gets worse, and fruit flies move in. In sandy ground where water drains away fast, the opposite happens: nutrients and leachate seep down instead. If there's a well or a small pond beside your plot, look even harder. One caveat — no study has actually applied landfill siting criteria to home gardens. Read this as a set of borrowed questions, not a standard.
To Try in the Garden Today
Come August, you work a base dressing into the beds where fall napa cabbage and daikon radish will go. The compost has to be finished by then, so now is a good time to look at where the bin is sitting.
- The morning after the rain stops, walk the garden and push a stake into any spot where water is still standing.
- Move the compost bin three or four steps off that spot, and set it somewhere even a few inches higher than the ground around it.
- Line the bottom of the bin with a palm-deep layer of dry leaves or rice hulls to catch the leachate.
- Steer clear of wells, water meters, and ponds, and give them a generous margin.
- If the ground slopes, position the bin so the downhill side isn't aimed at a neighbor's plot or the water's edge.
Find just one spot that still holds water the morning after the rain, and mark it. Then site this summer's compost anywhere but there.
Reference: a landfill site suitability study of Alappuzha, India, published in Scientific Reports.
