Kalaupapa National Historic Park

Earth Tub System Install: 2007



Kalaupapa is an isolated peninsula located at the base of 2000’ high sea cliffs on the north shore of Molokai, Hawaii. In 1866, all individuals with leprosy were exiled to this remote area. Since then, more than 8000 patients have lived and died at the Kalaupapa leper colony. The land still remains a refuge for the few remaining patients, and is recognized as a national historic site by the National Park Service.

Waste disposal was a real challenge for the Park Service because of the restricted access to Kalaupapa and the historic site status. They had tried using pack mules to transport waste up the cliffs but it was too time consuming. Installing an incinerator was too costly, as was flying out the waste. Composting organics on-site seemed like the most cost-effective solution.


In 2007, Green Mountain Technologies provided the park with two Earth Tubs to compost their food and garden waste. The Earth Tubs can process about 300 pounds of biodegradables a day. Due to an increase in staff and food waste, a third Earth Tub was added in 2012. An internal auger mixing system mixes and shreds the food waste as the cover is manually rotated. It takes Kalaupapa about a week to fill each tub, mixing new food waste daily. The tub then composts for two weeks while the new foodwaste goes to another tub. After three weeks, the compost is removed from the tub and placed into a pile to cure for about a month.


Patients and residents use the finished compost to nourish their vegetable gardens. Due to the high cost of flying in fresh produce, gardening is a popular hobby at Kalaupapa. The compost provides the plants with nutrients, and also keeps cost down for the busy gardeners.

Recently, GMT President and Chief Engineer, Michael Bryan-Brown, travelled to Kalaupapa to provide retraining for National Park Service Staff. Kalaupapa has high staff turnover, making the management of the Earth Tubs susceptible to operator error due a loss of knowledge during the transfer of responsibilities. The retraining session well equipped the operators with knowledge on how to use their tubs to make great compost.