This spring a series of interesting tests were conducted for RWR Consulting of Long Island, New York. The tests involved running lawn clippings through a Vincent dewatering screw press. A variety of grass clippings were pressed.

The need for the testing arose because of the increasing problem presented by residential lawn clippings. In many areas clippings have come to represent a significant proportion of urban residential waste going to landfill. Besides the cost that this implies, there is the additional problem of foul odor that comes from the decomposition of grass clippings.

We were pleased by the success of the testing. Typically, the incoming grass clippings were found to have 76% moisture content. With double pressing (i.e. running the pressed clippings through the press a second time) a reduction to 52% was achieved. In this process a cubic yard of lawn clippings was reduced by 60% to 0.4 cubic yards of pressed material and 3.5 gallons of press liquor.

Based on the results of this testing, five different New York towns approved funding for a project under the auspices of the Department of Environmental Conservation, State of New York. A multi-phase program was to run two and a half years, research being performed. The economics of various alternative uses of the pressed materials was to be investigated. Those included land mixing, animal fodder, liquid soil nutrient, mulching, and others.

We were told in 1997 that nothing had ever come of this. Residential lawn chemicals precluded most uses of the material. We chalked it up to a technical success but commercial failure.
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