Lawn Clippings

July 27, 1993
Rev. Jan 30, 1997

This spring a series of interesting tests were conducted for RWR Consulting of Long Island, New York. The tests involved running lawn clippings through the 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. 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 liquid.

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

[January 1997 update: Nothing has ever come of this. Residential lawn chemicals precluded most uses of the material.]

Issue 6