In pursuit of this new interest, I looked up more about he projects the Gaia Institute has been working on. One of the recent projects, beginning in 2002, involved the development of a storm water capture park called El Jardín del Paraíso in Manhattan’s Lower East Side. They restored a local community garden which had high lead contamination and enhanced it by allowing it to capture stormwater. They would accomplish this with a special layering of the soil which has two very important components: lead-binding chemicals and porous soil. The chemicals include phosphorous, iron, and manganese which also help increase root growth and encourage burrowing worms and insects. This in turn allows for a porous soil layer which holds the storm water from nearby rooftops and gray water from nearby buildings which would be collected in a manner which transfers them to the soil. As a result of this design, the Gaia Institute is able to promote ecological diversity and health in the urban city of Manhattan.
Source: http://www.thegaiainstitute.org/Gaia/El%20Jardin%20del%20Paraiso.html