New York’s iconic High Line, which attracts more than 7.5 million visitors a year, produces a lot of green waste. Indeed, in the next month or so this spikes as the Spring Cut takes place, with 200-300 individual volunteers tackling the task ahead of the new season’s growth.
Between 90 and 125 cubic yards of debris is created in March alone, estimates the Friends of the High Line’s director of horticulture, Andi Pettis. In the past, around half of the green waste has been composted on site, within a traditional four-bin system, but the rest has had to be shipped to the municipal compost facility.
However, last May the Friends acquired a composter that, by significantly speeding up the compost cycle, means all green waste can now be managed on-site.
It is located in a non-public storage area in one of the spaces on the Southern Spur, says Nicole De Feo, Friends of the High Line planning and design manager. Andi adds: “The impetus was that we have very little space and a lot of material to compost.” The new system, she says, has a small footprint and is very efficient.
The High Line is owned by the City of New York and maintained, operated and programmed by Friends of the High Line, in partnership with the New York City Department of Parks & Recreation. The last train ran in 1980 after which there was a battle to save the structure from demolition. Friends of the High Line was set up in 1999 to propose a viable way forward, culminating in ownership being donated by CSX Transportation Inc to the City in November 2005.
The first section opened to the public in mid-2009. Funding comes from the Friends’ membership, private donors, corporate partners and grants, plus revenue from retail sales and food vendors.
The species of perennials, grasses, shrubs and trees were chosen by planting designer, Piet Oudolf, for their drought-resistence, sustainability, and textural and colour variation, with around half being native species. In part, he took into account the species that had self-seeded during the years when the structure was derelict.
The High Line’s green roof system is designed to allow the plants to retain as much water as possible. In addition, there is an irrigation system installed with options for both automatic and manual watering.
There is a “beautiful sense of space on the High Line”, says Andi, and there is always consideration for wildlife, including pollinators, other insects and migrating birds, plus the microbiology of the soil (which at the outset was very sterile).
There are eleven full-time gardeners, with an additional three-to-five seasonal positions, plus the volunteer help (20-25 regular volunteers on any particular day and sometimes teams of corporate volunteers). Andi describes the gardens as “very intensive”. “All plants are front-of-bed for aesthetics, which means for visitors they are right there in your face so it is hard to absorb damage.”
The four bin system was relatively labour-intensive, with the need to manually turn it one or two times per week. Research into alternatives started a couple of years ago.
Although mostly used for food waste composting, the Rocket from Tidy Planet seemed a good fit. As well as taking up little space, it is a closed vessel so there is no smell and no problem with rats or leaching. From putting in waste at one end to extracting compost at the other takes two weeks. The only supplement to the green waste is some used coffee grounds from a nearby café.
The expectation is that 100 per cent of waste will now be handled. It saves money so that the composter should have paid for itself within a few years. There is no longer the cost of taking away excess waste, which included fees from the municipal facility, nor is there a need to buy compost (“we are closing that loop”, says Andi).