Calculate the Amount of Waste

A municipal solid waste department plans to separate a portion of the ferrous metal, newsprint and cardboard from its MSW waste stream. The department operates 50 collection trucks, each having a volume capacity of 16 yd³ and a compaction capability of 600 lb/yd³. Each truck collects an average of 8 loads per week over the year, with allowances for partial loads and downtime.

a)  Using the data provided, calculate the amount of waste in lb and yd³ transported to the landfill per year assuming the current generation rate remains the same and no recycling occurs.

b)  Estimate the savings in the volume of waste to be landfilled per year if 25% (by weight) of the waste stream is recycled. Assume the density of waste in landfill after compaction is 1000 lb/yd³.

(a)  Step 1.  Waste Volume Collected

  50 tucks * 16 yd³/load * 8 loads/wk * 52wk/yr = 332,800 yd³/yr

Step 2. Waste to be landfilled (truck compaction 600 lb/yd3)

  332,800 yd3/yr * 600 lb/yd³

 = 199,680,000 lb/yr

(b) Step 1. Recycling Volume

  199,680,000 lb * 0.25 = 49,920,000 lb/yr recycled material

  199,680,000 - 49,920,000 = 149,760,000 lb/yr to the landfill

Step 2. Volume that would have been occupied by the recycled material will the savings (remember the compacted density in the landfill is 1000 lb/yd³)

49,920,000lb / 1,000lb/yd³ = 49,920 yd³ / yr

Volume Savings = 49,920 yd³/yr  

Note: Density of refuse in collection is different than in the landfill